Proven Oil Reserves, as published by the CIA Factbook, 2009

The total estimated amount of oil in an oil reservoir, including both producible and non-producible oil, is called oil in place. However, because of reservoir characteristics and limitations in petroleum extraction technologies, only a fraction of this oil can be brought to the surface, and it is only this producible fraction that is considered to be reserves. The ratio of producible oil reserves to total oil in place for a given field is often referred to as the recovery factor. Recovery factors vary greatly among oil fields. The recovery factor of any particular field may change over time based on operating history and in response to changes in technology and economics. The recovery factor may also rise over time if additional investment is made in enhanced oil recovery techniques such as gas injection, surfactants injection, water-flooding,^[1] or microbial enhanced oil recovery.

Based on data from OPEC at the beginning of 2011 the highest proved oil reserves including non-conventional oil deposits are in Venezuela (20% of global reserves), Saudi Arabia (18% of global reserves), Canada (13% of global reserves), Iran (9%).^[2]

Because the geology of the subsurface cannot be examined directly, indirect techniques must be used to estimate the size and recoverability of the resource. While new technologies have increased the accuracy of these techniques, significant uncertainties still remain. In general, most early estimates of the reserves of an oil field are conservative and tend to grow with time. This phenomenon is called reserves growth.^[3]

Many oil-producing nations do not reveal their reservoir engineering field data and instead provide unaudited claims for their oil reserves. The numbers disclosed by some national governments are suspected of being manipulated for political reasons.^[4][5]

Classifications[link]

Schematic graph illustrating petroleum volumes and probabilities. Curves represent categories of oil in assessment. There is a 95% chance (i.e., probability, F95) of at least volume V1 of economically recoverable oil, and there is a 5-percent chance (F05) of at least volume V2 of economically recoverable oil.^[6]

All reserve estimates involve uncertainty, depending on the amount of reliable geologic and engineering data available and the interpretation of those data. The relative degree of uncertainty can be expressed by dividing reserves into two principal classifications—"proven" (or "proved") and "unproven" (or "unproved").^[6] Unproven reserves can further be divided into two subcategories—"probable" and "possible"—to indicate the relative degree of uncertainty about their existence.^[6] The most commonly accepted definitions of these are based on those approved by the Society of Petroleum Engineers (SPE) and the World Petroleum Council (WPC) in 1997.^[7]

Proven reserves[link]

Proven reserves are those reserves claimed to have a reasonable certainty (normally at least 90% confidence) of being recoverable under existing economic and political conditions, with existing technology. Industry specialists refer to this as P90 (i.e., having a 90% certainty of being produced). Proven reserves are also known in the industry as 1P.^[8][9]

Proven reserves are further subdivided into "proven developed" (PD) and "proven undeveloped" (PUD).^[9][10] PD reserves are reserves that can be produced with existing wells and perforations, or from additional reservoirs where minimal additional investment (operating expense) is required.^[10] PUD reserves require additional capital investment (e.g., drilling new wells) to bring the oil to the surface.^[8][10]

Until December 2009 "1P" proven reserves were the only type the U.S. Securities and Exchange Commission allowed oil companies to report to investors. Companies listed on U.S. stock exchanges must substantiate their claims, but many governments and national oil companies do not disclose verifying data to support their claims. Since January 2010 the SEC now allows companies to also provide additional optional information declaring "2P" (both proven and probable) and "3P" (proven + probable + possible) provided the evaluation is verified by qualified third party consultants, though many companies choose to use 2P and 3P estimates only for internal purposes.

Unproven reserves[link]

An oil well in Canada, which has the world's third largest oil reserves.

Unproven reserves are based on geological and/or engineering data similar to that used in estimates of proven reserves, but technical, contractual, or regulatory uncertainties preclude such reserves being classified as proven.^[11] Unproven reserves may be used internally by oil companies and government agencies for future planning purposes but are not routinely compiled. They are sub-classified as probable and possible.^[11]

Probable reserves are attributed to known accumulations and claim a 50% confidence level of recovery. Industry specialists refer to them as "P50" (i.e., having a 50% certainty of being produced). These reserves are also referred to in the industry as "2P" (proven plus probable).^[8]

Possible reserves are attributed to known accumulations that have a less likely chance of being recovered than probable reserves. This term is often used for reserves which are claimed to have at least a 10% certainty of being produced ("P10"). Reasons for classifying reserves as possible include varying interpretations of geology, reserves not producible at commercial rates, uncertainty due to reserve infill (seepage from adjacent areas) and projected reserves based on future recovery methods. They are referred to in the industry as "3P" (proven plus probable plus possible).^[8]

Fraud and incompetence

In the early 1980s the Penn Square Bank of Oklahoma engaged in wide scale lending to Oil and Gas groups with reserves used as collateral for the loans. Sometimes the bank officers ignored the engineering advice about reserve size and value in order to book the loan profit. The bank resold many of the loans as 'loan participations' to larger banks like Continental Illinois, Seattle First, Michigan National, and Chase Manhattan, whose officers also sometimes ignored engineering advice. When the oil market busted, many of these loans were called, and the true nature of the reserves used as loan collateral was discovered by Federal Deposit Insurance Corporation government investigators and creditors. Penn Square went bust, and Continental Illinois was the first Too Big to Fail bailout of the modern era.^[12]

Strategic petroleum reserves[link]

Many countries maintain government-controlled oil reserves for both economic and national security reasons. According to the United States Energy Information Administration, approximately 4.1 billion barrels (650,000,000 m³) of oil are held in strategic reserves, of which 1.4 billion is government-controlled (m³=cubic meters). These reserves are generally not counted when computing a nation's oil reserves.

Resources[link]

Unconventional oil resources are greater than conventional ones.^[13]

Cumulative oil production plus remaining reserves and undiscovered resources. United States not included.

A more sophisticated system of evaluating petroleum accumulations was adopted in 2007 by the Society of Petroleum Engineers (SPE), World Petroleum Council (WPC), American Association of Petroleum Geologists (AAPG), and Society of Petroleum Evaluation Engineers (SPEE). It incorporates the 1997 definitions for reserves, but adds categories for contingent resources and prospective resources.^[6]

Contingent resources are those quantities of petroleum estimated, as of a given date, to be potentially recoverable from known accumulations, but the applied project(s) are not yet considered mature enough for commercial development due to one or more contingencies. Contingent resources may include, for example, projects for which there are currently no viable markets, or where commercial recovery is dependent on technology under development, or where evaluation of the accumulation is insufficient to clearly assess commerciality.

Prospective resources are those quantities of petroleum estimated, as of a given date, to be potentially recoverable from undiscovered accumulations by application of future development projects. Prospective resources have both an associated chance of discovery and a chance of development.

The United States Geological Survey uses the terms technically and economically recoverable resources when making its petroleum resource assessments. Technically recoverable resources represent that proportion of assessed in-place petroleum that may be recoverable using current recovery technology, without regard to cost. Economically recoverable resources are technically recoverable petroleum for which the costs of discovery, development, production, and transport, including a return to capital, can be recovered at a given market price.

"Unconventional resources" exist in petroleum accumulations that are pervasive throughout a large area. Examples include extra heavy oil, natural bitumen, and oil shale deposits. Unlike "conventional resources", in which the petroleum is recovered through wellbores and typically requires minimal processing prior to sale, unconventional resources require specialized extraction technology to produce. For example, steam and/or solvents are used to mobilize bitumen for in-situ recovery. Moreover, the extracted petroleum may require significant processing prior to sale (e.g., bitumen upgraders).^[6] The total amount of unconventional oil resources in the world considerably exceeds the amount of conventional oil reserves, but are much more difficult and expensive to develop.

Estimation techniques[link]

Example of a production decline curve for an individual well

The amount of oil in a subsurface reservoir is called oil in place (OIP).^[10] Only a fraction of this oil can be recovered from a reservoir. This fraction is called the recovery factor.^[10] The portion that can be recovered is considered to be a reserve. The portion that is not recoverable is not included unless and until methods are implemented to produce it.

There are a number of different methods of calculating oil reserves. These methods can be grouped into three general categories: "volumetric", "material balance", and "production performance". Each method has its advantages and drawbacks.^[10][11]

Volumetric method[link]

Volumetric methods attempt to determine the amount of oil in place by using the size of the reservoir as well as the physical properties of its rocks and fluids. Then a recovery factor is assumed, using assumptions from fields with similar characteristics. OIP is multiplied by the recovery factor to arrive at a reserve number. Current recovery factors for oil fields around the world typically range between 10 and 60 percent; some are over 80 percent. The wide variance is due largely to the diversity of fluid and reservoir characteristics for different deposits.^[14][15][16] The method is most useful early in the life of the reservoir, before significant production has occurred.

Materials balance method[link]

The materials balance method for an oil field uses an equation that relates the volume of oil, water and gas that has been produced from a reservoir and the change in reservoir pressure to calculate the remaining oil. It assumes that, as fluids from the reservoir are produced, there will be a change in the reservoir pressure that depends on the remaining volume of oil and gas. The method requires extensive pressure-volume-temperature analysis and an accurate pressure history of the field. It requires some production to occur (typically 5% to 10% of ultimate recovery), unless reliable pressure history can be used from a field with similar rock and fluid characteristics.^[11]

Production decline curve method[link]

The decline curve method uses production data to fit a decline curve and estimate future oil production. The three most common forms of decline curves are exponential, hyperbolic, and harmonic. It is assumed that the production will decline on a reasonably smooth curve, and so allowances must be made for wells shut in and production restrictions. The curve can be expressed mathematically or plotted on a graph to estimate future production. It has the advantage of (implicitly) including all reservoir characteristics. It requires a sufficient history to establish a statistically significant trend, ideally when production is not curtailed by regulatory or other artificial conditions.^[11]

Reserves growth[link]

Experience shows that initial estimates of the size of newly discovered oil fields are usually too low. As years pass, successive estimates of the ultimate recovery of fields tend to increase. The term reserve growth refers to the typical increases in estimated ultimate recovery that occur as oil fields are developed and produced.^[3]

Estimated reserves by country[link]

bbl = barrel of oil

Countries with largest oil reserves

Most of the world's oil reserves are in the Middle East.^[17]

OPEC countries[link]

There are doubts about the reliability of official open reserves estimates, which are not provided with any form of verification that meet external reporting standards.^[20]

Since a system of country production quotas was introduced in the 1980s, partly based on reserves levels, there have been dramatic increases in reported reserves among OPEC producers. In 1983, Kuwait increased its proven reserves from 67 Gbbl (10.7×10^⁹ m³) to 92 Gbbl (14.6×10^⁹ m³). In 1985–86, the UAE almost tripled its reserves from 33 Gbbl (5.2×10^⁹ m³) to 97 Gbbl (15.4×10^⁹ m³). Saudi Arabia raised its reported reserve number in 1988 by 50%. In 2001–02, Iran raised its proven reserves by some 30% to 130 Gbbl (21×10^⁹ m³), which advanced it to second place in reserves and ahead of Iraq. Iran denied accusations of a political motive behind the readjustment, attributing the increase instead to a combination of new discoveries and improved recovery. No details were offered of how any of the upgrades were arrived at.^[20][21]

The following table illustrates these rises.

OPEC countries

oil reserves of OPEC 1980–2005

The sudden revisions in OPEC reserves, totaling nearly 300 bn barrels, have been much debated.^[22] Some of it is defended partly by the shift in ownership of reserves away from international oil companies, some of whom were obliged to report reserves under conservative US Securities and Exchange Commission rules.^[20][23] The most prominent explanation of the revisions is prompted by a change in OPEC rules which set production quotas (partly) on reserves. In any event, the revisions in official data had little to do with the actual discovery of new reserves.^[20]

Total reserves in many OPEC countries hardly changed in the 1990s.^[20] Official reserves in Kuwait, for example, were unchanged at 96.5 Gbbl (15.34×10^⁹ m³) (including its share of the Neutral Zone) from 1991 to 2002, even though the country produced more than 8 Gbbl (1.3×10^⁹ m³) and did not make any important new discoveries during that period.^[20] The case of Saudi Arabia is also striking, with proven reserves estimated at between 260 and 264 billion barrels (4.20×10¹⁰ m³) in the past 18 years, a variation of less than 2%,^[20] while extracting approximately 60 billion barrels (9.5×10⁹ m³) during this period.

Sadad al-Huseini, former head of exploration and production at Saudi Aramco, estimates 300 Gbbl (48×10^⁹ m³) of the world's 1,200 Gbbl (190×10^⁹ m³) of proven reserves should be recategorized as speculative resources, though he did not specify which countries had inflated their reserves.^[24] Dr. Ali Samsam Bakhtiari, a former senior expert of the National Iranian Oil Company, has estimated that Iran, Iraq, Kuwait, Saudi Arabia and the United Arab Emirates have overstated reserves by a combined 320–390bn barrels and has said, "As for Iran, the usually accepted official 132 billion barrels (2.10×10¹⁰ m³) is almost one hundred billion over any realistic assay."^[25] Petroleum Intelligence Weekly reported that official confidential Kuwaiti documents estimate reserves of Kuwait were only 48 billion barrels (7.6×10^⁹ m³), of which half were proven and half were possible. The combined value of proven and possible is half of the official public estimate of proven reserves.^[21]

In July 2011, OPEC's Annual Statistical Review showed Venezuela's reserves to be larger than Saudi Arabia's.^[26]

Prospective resources[link]

Arctic prospective resources[link]

Location of Arctic Basins assessed by the USGS

A 2008 United States Geological Survey estimates that areas north of the Arctic Circle have 90 billion barrels (1.4×10¹⁰ m³) of undiscovered, technically recoverable oil and 44 billion barrels (7.0×10⁹ m³) of natural gas liquids in 25 geologically defined areas thought to have potential for petroleum. This represented 13% of the expected undiscovered oil in the world. Of the estimated totals, more than half of the undiscovered oil resources were estimated to occur in just three geologic provinces—Arctic Alaska, the Amerasia Basin, and the East Greenland Rift Basins. More than 70% of the mean undiscovered oil resources was estimated to occur in five provinces: Arctic Alaska, Amerasia Basin, East Greenland Rift Basins, East Barents Basins, and West Greenland–East Canada. It was further estimated that approximately 84% of the oil and gas would occur offshore. The USGS did not consider economic factors such as the effects of permanent sea ice or oceanic water depth in its assessment of undiscovered oil and gas resources. This assessment was lower than a 2000 survey, which had included lands south of the Arctic Circle.^[27][28][29]

Miscellaneous prospective resources[link]

In October 2009, the USGS updated the Orinoco tar sands (Venezuela) value to 513 billion barrels (8.16×10¹⁰ m³).^[30]

The Exclusive Economic Zone is a delineated offshore area, mostly to the west and north of Cuba, which, under international agreements, is owned by Cuba. This 112,000-square-kilometer zone has been divided into 59 exploration blocks. A 2004 joint partnership between a Spanish oil company and Cuba's state oil company (CUPET) estimated Cuba's off-shore reserves to be able to produce ultimately between 4.6 and 9.3 billion barrels of crude oil.^[31]

The US Geological Survey (USGS) estimates that Cuba has resources up to 9 billion barrels (1.4×10⁹ m³) of oil. In October 2008, the Cuban government announced that it had discovered oil basins that would double its total oil resources to 20 billion barrels (3.2×10⁹ m³).^[32] Note that, consistent with the definitions of reserves and resources as given in the above sections, at this stage (June 2009), given no commercial discoveries to date, all recoverable oil estimates in the Exclusive Economic Zone (EEZ) are prospective resources estimates and not reserves estimates.

See also[link]

Energy portal

• Decline curve analysis
• Global strategic petroleum reserves
• Oil exploration
• Peak oil
• Petroleum Industry
• Strategic Petroleum Reserve

Energy and resources:

• Energy security
• World energy resources and consumption
• List of countries by natural gas proven reserves

References[link]

• http://www.opec.org/opec_web/en/data_graphs/330.htm

External links[link]

• OPEC Annual Statistical Bulletin
• Energy Supply page on the Global Education Project web site, including many charts and graphs on the world's energy supply and use
• Oil reserves (most recent) by country

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The fatal shooting of Trayvon Martin by George Zimmerman took place on February 26, 2012, in Sanford, Florida, United States. Trayvon Martin was a 17-year-old African American male who was unarmed.^[2] George Zimmerman was a 28-year-old multi-racial Hispanic American,^{[3][Note 1]} who was the community watch coordinator for the gated community where the shooting took place.^{[5][6][7][8][9]}

While on a private errand, Zimmerman saw Martin walking inside the gated community where Martin and his father were visiting his father's fiancée. Zimmerman called the Sanford Police Department to report Martin's behavior as suspicious.^[10] Shortly afterwards, there was an altercation, which ended with Zimmerman fatally shooting Martin once in the chest at close range.^{[11][12][13][14][15]}

When police arrived on the scene Zimmerman told them that Martin had attacked him and that he had shot Martin in self-defense.^[2][16] Zimmerman was bleeding from the nose and two vertical lacerations on the back of his head.^[17][18] EMTs treated Zimmerman at the scene, after which he was taken to the Sanford Police Department. Zimmerman was detained and questioned for approximately five hours.^[19][18] A statement was videotaped, and he was then released without being charged.^[17] Police said that they had not found evidence to contradict his assertion of self-defense.^{[20][21][22][23][24]}

The circumstances of Martin's death, the initial decision not to charge Zimmerman, and questions about Florida's Stand Your Ground law received national and international attention. Allegations of racist motivation for the shooting and police conduct contributed to public demands for Zimmerman's arrest.^[25][26][27] A Special Prosecutor was appointed to take over the investigation and on April 11, 2012, she chose to file charges of murder in the second degree against Zimmerman.^[28][29] Zimmerman then turned himself in and was placed in custody.^[30][31] On April 20, the judge approved Zimmerman's bail on a $150,000 bond.^[32] He was released from jail on April 23 and is required to wear an electronic monitoring device until trial.

People involved in the case[link]

George Zimmerman

Trayvon Martin[link]

Trayvon ( /treɪˈvɔːn/ tray-VAWN) Benjamin Martin (February 5, 1995 – February 26, 2012) was the son of Sybrina Fulton and Tracy Martin, who were divorced in 1999.^[33] The autopsy report stated he was 5 feet 11 inches and 158 pounds.^[34]

He was a high school junior in the Miami, Florida, area and had recently turned 17.^[35][36] Martin lived with his mother and older brother in Miami Gardens, Florida. He had been taken by his father to Sanford, Florida, following a ten-day suspension from high school.^{[37][38] [39]} They were visiting his father's fiancée and her son at her townhome in The Retreat at Twin Lakes in Sanford on the day Martin was fatally shot.^[40]

George Zimmerman[link]

George Michael Zimmerman^[41] was born on October 5, 1983, in Manassas, Virginia,^[42] and is the son of Robert Zimmerman, Sr., a retired Virginia magistrate,^[43] and Peruvian-born Gladys (née Mesa) Zimmerman.^[5][8] He grew up in what his father has described as a "multiracial family" (one of his maternal great-grandfathers was of Afro-Peruvian background),^[44] and was raised in his mother's Catholic religion (his father was Baptist).^[4] Zimmerman's voter registration record lists him as Hispanic and a Democrat.^[45][46]

Zimmerman's height is shown as 5'8" and his weight as 185 pounds on his Seminole County Sheriff's Office Inmate Booking Information dated 4/11/2012.^[47] Zimmerman's height is shown as 5'7" and his weight at 200 pounds on the Sanford Police Department Offense Report for 2/26/2012.^[48]

In 2009, he moved with his wife to The Retreat at Twin Lakes in Sanford, Florida, a multi-ethnic^[49] gated community, where the shooting occurred.^[50][51] He was employed as an insurance underwriter prior to the shooting^[52] and was in his final semester at Seminole State College for an Associates degree in Criminal Justice.^[53] His goal was to become a police officer.^[54]

Zimmerman's role in the neighborhood watch[link]

As the only person to volunteer when the homeowners association wanted to organize a community watch,^[55] Zimmerman was appointed coordinator by his neighbors, according to Wendy Dorival, Neighborhood Watch organizer for the Sanford Police Department.^[56] The homeowner's association told residents who saw suspicious activity to call Zimmerman if they could not contact the police.^[57] "[Zimmerman] once caught a thief and an arrest was made," said Cynthia Wibker, secretary of the homeowners association.^[55]

Police had been called to The Retreat at Twin Lakes 402 times from January 1, 2011, to February 26, 2012.^[55] Zimmerman was the caller on 11 of those calls in that time frame. Crimes committed at The Retreat in the year prior to Martin's death included eight burglaries, nine thefts, dozens of break-ins (at least one with a woman and infant upstairs) and one shooting. In September, Zimmerman was asked to head up a neighborhood watch.^[55] The City of Sanford posted a "George Zimmerman 911 Call History" listing 46 calls by him between 2004 and the 2012 shooting.^{[58][59][60][Note 2]}

Zimmerman had been licensed to carry a firearm since November 2009. An officer with Seminole County Animal Services had told Zimmerman not to rely on pepper spray to fend off a loose pit bull in the neighborhood; he told Zimmerman to "get a gun." Zimmerman had called the owner to complain about the dog after it had cornered his wife, and then called animal services on two other occasions to report that the dog was running loose.^[53]

Sanford police chief Bill Lee stated that neighborhood watch volunteers are not encouraged to carry a gun but have a Constitutional right to do so.^[55] Lee further stated, "Mr. Zimmerman was not acting outside the legal boundaries of Florida Statute by carrying his weapon when this incident occurred."^[64]

Sanford Police volunteer program coordinator Wendy Dorival, told the Miami Herald that she met Zimmerman in September, 2011 at a community neighborhood watch presentation. “I said, ‘If it’s someone you don’t recognize, call us. We’ll figure it out,’  ‘Observe from a safe location.’ Dorival said.”^[55]

Police[link]

According to ABC News and other media organizations, multiple sources had indicated to them that Chris Serino, the lead investigator for the Sanford Police on the night of the shooting, stated in a February 26, 2012 affidavit that he was unconvinced by Zimmerman's version of events.^[65] Based on Serino's February 26 affidavit, police sought an arrest warrant for Zimmerman, however that request was denied by the Office of the State Attorney for insufficient evidence.^{[65][66][67][21][22][23][68]}

On March 13, 2012, Chris Serino sent a capias request to the state's attorney asking for George Zimmerman to be charged with manslaughter.^[69][70] Serino stated in the request that "the encounter between George Zimmerman and Trayvon Martin was ultimately avoidable by Zimmerman, if Zimmerman had remained in his vehicle and waited the arrival of law enforcement or conversely if he had identified himself to Martin as a concerned citizen and initiated dialog (sic) in an effort to dispel each party's concern". "There is no indication that Trayvon Martin was involved in any criminal activity at the time of the encounter."^[71] The state attorney's office initially did not act on the request for an arrest warrant.^[70]

On March 16, 2012, Serino told the Orlando Sentinel that his investigation had turned up no reliable evidence that cast doubt on Zimmerman's account, that he had acted in self-defense. "The best evidence we have is the testimony of George Zimmerman, and he says the decedent was the primary aggressor in the whole event, everything I have is adding up to what he says."^[67]

When special prosecutor Angela Corey was asked by the Miami Herald to confirm that the Sanford Police had initially recommended a manslaughter charge, she stated, "I don't know about that, but as far as the process, I can tell you that the police went to the state attorney with a capias request, meaning; We're through with our investigation and here it is for you." A capias is a request for charges to be filed. A source in the Seminole County State Attorney's office told the Miami Herald, "We get capias warrants all the time. That doesn't mean we file charges right away. We investigate to see if it's appropriate. That's the responsible thing to do.^[72]

Bill Lee, Chief of Police at the time of the shooting, received criticism for his role in the case. The Sanford city commission, including the Mayor, passed a motion of no confidence in regards to Chief Lee, and his handling of the case^[73] although the vote was advisory only.^[74] On March 22, 2012, Lee announced that he had temporarily stepped down from his position as chief of police, stating "my involvement in this matter is overshadowing the process."^[75] On April 23, 2012, the city of Sanford announced that Police Chief Bill Lee would resign but city commissioners voted to reject the resignation. Some commissioners had concerns about the fairness of Lee losing his job and the mayor stated he preferred to wait for the results of an investigation into Lee and his department. Lee was to remain on paid leave.^[76]

State Attorneys[link]

Norm Wolfinger was the state's attorney initially responsible for the case.^[77] He is responsible for prosecutions in Brevard and Seminole counties, where the shooting occurred.^[78]

On March 22, 2012, Florida Governor Rick Scott announced that he was appointing Angela Corey to be Special Prosecutor and that she would be investigating the case instead of Wolfinger.^[79] She is the State attorney for Duval, Clay and Nassau counties.^[80] After several weeks of investigation, Corey announced on April 11, 2012, that Zimmerman had been charged with second-degree murder.^[28][81]

George Zimmerman's attorneys[link]

Craig Sonner and Hal Uhrig were the first lawyers to represent George Zimmerman.^[82][83] On April 10, 2012, they announced at a news conference that they were withdrawing from the case as Zimmerman was no longer returning their calls and had been acting against their advice.^[84] According to Harvard law professor Alan Dershowitz, Sonner and Uhrig should not have disclosed those details and other information about Zimmerman after they had stopped representing him, because of considerations of attorney-client privileged information.^[85]

On April 11, 2012, it was announced that Zimmerman was represented by a new attorney, Mark M. O'Mara,^[30] who is board-certified as a criminal trial specialist.^[86] O'Mara pointed out that a small number of murder cases actually go to trial, with many cases resulting in a plea bargain. "We're not taking any possibilities off the table how this case gets resolved," he said. O'Mara described the intensely debated encounter between Martin and Zimmerman as resulting in "a deceased child," and also said, "Obviously, it was a horrible intersection of two young men's lives and it ended in tragedy."^[87][88] George Zimmerman's defense team has set up a Twitter account, a Facebook page and a website with a defense fund registered with the Florida Division of Consumer Services. O'Mara stated on the website that "Using social media in a high-profile lawsuit is new, and relatively unprecedented, but that is only because social media itself is relatively new. We feel it would be irresponsible to ignore the robust online conversation, and we feel equally as strong about establishing a professional, responsible, and ethical approach to new media."^[89][90][91]

Martin family attorneys[link]

Benjamin Crump, the lawyer representing the interests of the Martin family, operates a law firm in Tallahassee, Florida, with his partner Daryl Parks. The firm has eight lawyers who focus on wrongful death, malpractice, personal injury and civil rights.^[92][93] In 2006, Crump sued to have the video released in the case of Martin Anderson, a teenager who died at a boot camp run by the Bay County, Florida, Sheriff's Office.^[92][94][95] The Martin family is also represented by Natalie Jackson, an Orlando civil rights attorney.^[96][97]

Shooting[link]

Martin was staying with his father at the home of his father's fiancée.^[40] On his return from a convenience store,^[98][99] he was observed by Zimmerman,^[100] who was driving in his vehicle on a personal errand.^[101] At the end of their interaction, Martin was shot 70 yards (64 meters) from the rear door of the fiancée's townhouse.^{[102][Note 3]}

Zimmerman's early February, 2012, cell phone call to police[link]

Three weeks prior to the shooting, on February 2, 2012, Zimmerman placed a call to the Sanford Police Department to report a young man peering into the windows of an empty Twin Lakes home. Zimmerman was told a police car was on the way, and he followed protocol, awaiting their arrival. By the time police showed up, the suspect had fled. On February 6, 2012, workers witnessed two young black men lingering in the yard of a Twin Lakes resident around the same time her home was burglarized. A new laptop and some gold jewelry were stolen. The next day police discovered the stolen laptop in the backpack of a young black man, which led to his arrest. Zimmerman identified this young man as the same person he had spotted peering into windows on February 2.^[53]

Zimmerman's February 26, 2012, call to police[link]

While driving through the Twin Lakes neighborhood, at approximately 7:09:34 PM, February 26, 2012, Zimmerman used his cell phone to call the non-emergency number of the Sanford Police Department^[104] to report what he considered suspicious behavior by Martin. "We've had some break-ins in my neighborhood, and there's a real suspicious guy."^[53] He described Martin as "just walking around looking about" in the rain.^[105] The police dispatcher tape recorded him saying, "This guy looks like he is up to no good or he is on drugs or something." He further stated that the person he was observing had his hand in his waistband, was holding something in his other hand, and was walking around slowly in the rain "looking at all the houses."^[106] On the recording of the call, Zimmerman is heard commenting "these assholes, they always get away."^{[107][108][109]}

At 2:07 minutes into his call to the police, Zimmerman says, "he's running." At 2:37 minutes, Zimmerman tells the dispatcher, "he ran." The sound of an "open door" chime, a change in Zimmerman's voice and the sound of wind indicate that Zimmerman has left his vehicle, prompting the dispatcher to ask if Zimmerman is following Martin. When Zimmerman confirms that he is, the dispatcher says, "We don't need you to do that."^[110] Zimmerman says "OK." Asked if he "want(s) to meet with the officer," Zimmerman says "yeah" and gives directions to where his vehicle is parked but is unable to provide an address. He also tells the dispatcher the numbers of his street address, and then at 3:35 adds, "Oh crap, I don't want to give it all out. I don't know where this kid is." The dispatcher asks him if he wants to meet the police at the mailboxes,^{[Note 3, 4th picture]} and he at first agrees but then says, "Actually, could you have him call me, and I'll tell him where I'm at?" to which the dispatcher replies, "No problem."^[111] Zimmerman appears to hang up at the 4:05 mark. The recording ends at the 4:11 mark, approximately 7:13:41 PM.

Martin cell phone call from girlfriend[link]

Around the time of the incident, Martin was talking on his cellphone to his girlfriend, according to Attorney Benjamin Crump and State Prosecutor's, which was confirmed by phone company records.^[113][114] She called at 7:12 PM, although phone company records round down call times. Hence, the actual call was between 7:12:00 and 7:12:59 PM.^[115][116] She was interviewed by Crump who made a statement for her, as her parents requested her anonymity, and gave a sworn interview recorded by a state prosecutor.^[113][114]

Martin's girlfriend said that he described a man as "crazy and creepy," who was on the phone watching him from a vehicle, before the man started following him.^[114] The friend said that she told Martin to run to the townhouse, where he was staying with his father and the father's girlfriend.^[114] She said that Martin told her that he had lost the man and then noticed he was being pursued again.^[113][114] She then heard Martin say "What are you following me for?" followed by a man's voice responding, "What are you doing around here?"^[113][114] She said that she heard the sound of pushing^[113] and then heard Martin say what sounded like "get off, get off," and the call ended.^[114] She attempted to call him back immediately, but was unable to reach him.^[117]

Sanford Police arrival and initial investigation[link]

Police officer Timothy Smith arrived at the scene at approximately 7:17 PM. He reported finding Zimmerman standing near Martin, who was lying face down in the grass and unresponsive.^[14][17] At that time, Zimmerman stated to Smith that he had shot Martin and was still armed. Smith handcuffed Zimmerman and removed his weapon from him. Smith observed that Zimmerman's back was wet and covered with grass and he was bleeding from the nose and the back of his head.^[14][118]

Ricardo Ayala, the second officer to arrive that night, noticed Officer Smith had Zimmerman in custody, then observed Martin lying face down in the grass and attempted to get a response from him. At this time, Sgt. Anthony Raimondo arrived and together with Ayala began CPR. Paramedics from Sanford Fire and Rescue arrived and continued CPR, finally declaring him dead at 7:30 PM^[14]

Other officers who had arrived by this time secured the area and made contact with neighbors in the area and obtained statements from witnesses at the scene. They did not realize Zimmerman had been in a vehicle, however, so it was moved before they could seize it.^[119] Zimmerman was treated and released by paramedics while still at the scene of the incident.^[14][118] After placing Zimmerman in his police vehicle, Officer Smith heard Zimmerman say, "I was yelling for someone to help me, but no one would help me."^[14][120] Zimmerman was then transported to the Sanford Police Department where he was questioned by investigators for approximately five hours.^[14][19]

Martin's body was taken to the morgue where he was tagged as a John Doe as he was not carrying any identification.^[23] Martin's father, Tracy Martin, called to file a Missing Persons report early on February 27 and police officers arrived at his fiancée's condo with photographs of his dead son around 9:20 am.^[23][121]

Witness accounts[link]

A witness to the confrontation just prior to the shooting stated that Martin was on top of Zimmerman and punching him, while Zimmerman was yelling for help. This witness, who identified himself as "John", stated that "the guy on the bottom, who had a red sweater on, was yelling to me, 'Help! Help!' and I told him to stop, and I was calling 911".^[123] He went on to say that when he got upstairs and looked down, "the guy who was on the top beating up the other guy, was the one laying in the grass, and I believe he was dead at that point.".^[123][124]

A 13-year-old boy walking his dog saw a man on the ground shortly before the shooting and identified him as wearing red.^{[125][126][127]} His mother later disputed the testimony and claimed that the police pressured him into choosing what color the man was wearing, and that her son could not see any details in the dark. She also stated that the police waited five days before requesting to even question her son and said the lead homicide investigator told her he did not believe the shooting was self defense.^[128][68]

Mary Cutcher and her roommate, Selma Mora Lamilla, appeared on AC 360 and Cutcher stated that she believes "there was no punching, no hitting going on at the time, no wrestling" just prior to the shooting, but admitted that she neither saw the shooting nor the preceding altercation.^{[129][130][131]} Cutcher and her roommate heard the pair in their backyard and a "very young voice" whining, with no sounds of a fight. They heard a gunshot; the crying stopped immediately, and they saw Zimmerman on his knees straddling Martin on the ground.^[129][131] Mary Cutcher phoned police after the fatal shooting and said the black man was standing over another man, although Trayvon Martin was already dead.^[132] According to the Orlando Sentinel article, "Police spokesman Sgt. Dave Morgenstern [on March 15] issued a statement disputing Cutcher's version of events, calling her statements to WFTV "inconsistent with her sworn testimony to police."^[133] However, Cutcher and her roommate maintain that their account of the incident to the police did not agree with Zimmerman's, and they demanded the police retract that incorrect statement.^[130]

On March 29, 2012, an eyewitness referred to as a male said that he saw two men on the ground scuffling, then heard the shooting, and saw Zimmerman walk away with no blood on him.^[134][135] The witness later appeared on CNN AC360 referred to as a female, giving more details on her account. She pointed out that she heard an argument between a younger and an older voice. The whole time she witnessed the incident the scuffling happened on the grass. She said that the larger man, who walked away after the gunshot, was on top, and that it was too dark to see blood on his face.^[136]

A witness who arrived shortly after the shooting revealed photos he took that night that showed "blood trickling down the back of Zimmerman's head from two cuts. It also shows a possible contusion forming on the crown of his head". In revealing the photo to ABC News in mid-April, he noted he heard but didn't see the scuffle, but was one of the first to arrive, and was the first to talk to Zimmerman after the shooting.^[18]

After the prosecutors made some discovery information available, the Orlando Sentinel quoted an eye witness statement which said a man had "witnessed a black male, wearing a dark colored 'hoodie' on top of a white or Hispanic male who was yelling for help." The witness said the black male was throwing punches "MMA [mixed martial arts] style." After hearing a "pop," he saw the black male "laid out on the grass."^[137][138] When the witness was interviewed several weeks later, after giving his first statement, he thought the black male was either punching or pinning the lighter skinned male underneath him. He was no longer certain who was calling for help, having not seen their mouths in the dark. He was still certain that the black male had been on top of the lighter-skinned male.^[139]

Martin's mother says the shouting for help heard on some of the 9-1-1 calls is her son's voice.^[140] Zimmerman's father, along with other relatives, have reviewed the 9-1-1 calls and identified the person screaming for help as Zimmerman.^[141] In a report, lead investigator Serino said that on Feb. 28, two days after the shooting, he played the 911 tapes for Tracy Martin, Trayvon's father. "I asked Mr. Martin if the voice calling for help was that of his son. Mr. Martin, clearly emotionally impacted by the recording, quietly responded 'No.'" Martin has since told reporters he was uncertain at that time, but that when he heard an enhanced recording on March 16 he was convinced it was his son calling for help.^[142] Martin's mother's perspective is relied upon in Corey's Affidavit of Probable Cause for second degree murder. The Zimmerman family perspective is not mentioned in the charging document.^[143]

Sanford police station[link]

The back of Zimmerman's head at the police station.^[144]

After arriving at the police station, Zimmerman was placed in an interview room where he was interviewed by Investigator D. Singleton.^[14][145] The gun, a black Kel-Tec PF-9 9mm semi-automatic pistol, taken from Zimmerman at the scene, was placed into evidence.^[15][146] Sometime after 11:21 AM Crime Scene Tech D. Smith photographed Zimmerman's injuries and hands and used a Gunshot Residue Kit to collect GSR in Interview Room 2 at Sanford PD. Zimmerman's clothes were taken as evidence after his wife arrived with a change of clothes.^[147]

Zimmerman was not administered a drug or alcohol test.^[17] Peter Bella, a retired Chicago Police forensic investigator, stated in an article for the Washington Times, "Except for DUIs, police cannot test suspects for drugs or alcohol, unless the accused demands or consents to it, or they get a warrant".^{[148][149][150]}

He also underwent voice stress analysis, a type of lie detector test, which he passed, and the day after the shooting he re-enacted the incident for police.^[119]

The lead homicide investigator on the case, Chris Serino, filed an affidavit the night of the incident saying he was unconvinced by Zimmerman's account and recommending charging Zimmerman with manslaughter, but was informed by State Attorney Wolfinger's office that there was not enough evidence to obtain a conviction.^[21] Zimmerman was eventually released without charges.^[17] TheGrio.com reported that Wolfinger met with police leaders on the night of the shooting while Zimmerman was still in police custody,^[151] but Wolfinger denies this.^[77] Instead, his spokesman said, police consulted that night with the prosecutor on call, Kelly Jo Hines.^[152]

George Zimmerman's account of events[link]

On the night of the shooting, and afterwards, Zimmerman described in detail, for the police and others, what took place.^{[141][153][154][155]}

Zimmerman said he was driving to the grocery store when he spotted Trayvon Martin walking through the neighborhood. Zimmerman's father said that, while his son was not on duty that night as Neighborhood Watch captain, there had been many break-ins and he thought it suspicious that someone he didn't recognize was walking behind the town homes instead of on the street or the sidewalk. Zimmerman therefore called a non-emergency police line to report Martin's behavior and summon police.^[156][157] During the call, Zimmerman told the dispatcher that Martin was "coming to check me out."^[10] A source to the Orlando Sentinel said that Zimmerman later told investigators that at one point Martin was circling his vehicle, and he rolled up his window to avoid a confrontation.^[153]

After telling the police dispatcher that Martin "ran,"^[10] Zimmerman left his vehicle and followed him on foot.^[153] The dispatcher confirmed that Zimmerman was following Martin and then said, "OK, we don't need you to do that." Zimmerman replied with "OK" and stated that Martin got away.^[10] After a discussion about where Zimmerman would meet police, the call ended, and Zimmerman told investigators he was returning to his vehicle when Martin approached him from his left rear and confronted him.^[153][154] According to Zimmerman's father, Martin asked Zimmerman, "Do you have a fucking problem?" Zimmerman replied "No, I don't have a problem", and while Zimmerman reached for his cell phone Martin said, "Well, you do now" or something similar,^[141][154] then punched him in the face, knocking him down, and began beating his head against the sidewalk.^[153][154] Zimmerman said he called out for help while being beaten, and at one point Martin covered his mouth to muffle the screams.^[153][154] According to Zimmerman's father, during the struggle while Martin was on top of Zimmerman, Martin saw the gun his son was carrying and said something to the effect of “You’re gonna die now” or “You’re gonna die tonight” and continued to beat Zimmerman.^[141] Zimmerman and Martin struggled over the gun, and Zimmerman shot Martin once in the chest at close range, in self-defense.^{[153][154][155][Note 4]}

Phone recordings[link]

Recordings of eight calls to the police made on the night of the shooting were released by the Sanford police on March 17, 2012.^[106][158] Early press reports incorrectly indicated that the recordings included the sound of a single shot followed by a voice pleading or begging for help, and then a second shot, after which the voice immediately stopped. Later reports indicate that the gun was fired only once.^[159] Zimmerman told police at the scene that he had cried out for help.^[154] The statement was corroborated by an eyewitness who said that Martin was on top of Zimmerman, beating him, as Zimmerman called for help.^[123] One witness, who had only heard but not seen the events, believed Martin was the one calling for help, and said that the police tried to get her to change her testimony to their assertion that it was Zimmerman calling for help.^[160]

Independent experts vary in their interpretations of the low-quality audio of the phone recordings.^[161]The FBI was not able to determine whether it was Zimmerman or Martin who could be heard crying out for help in 911 calls, citing both poor audio quality and "the extreme emotional state of the person screaming."^[162][163]

Ongoing investigation[link]

Zimmerman was originally not charged with any crime. He asserted the right of self-defense and investigators said they could find no evidence disproving that assertion.^[16][164] The State Attorney's office and Police Chief Lee said they did not have enough evidence to arrest Zimmerman. "In this case Mr. Zimmerman has made the statement of self-defense," Lee said. "Until we can establish probable cause to dispute that, we don't have the grounds to arrest him." In response to criticisms of the investigation, Lee responded that "We are taking a beating over this" and defended the investigation.^[165] "This is all very unsettling. I'm sure if George Zimmerman had the opportunity to relive Sunday, February 26, he'd probably do things differently. I'm sure Trayvon would, too."^[55]

On March 20, 2012, State attorney Norm Wolfinger announced that a Seminole County grand jury would be convened on April 10, to investigate the death of Martin.^{[166][167][168]} However, State attorney Angela Corey, who was assigned to the case by Governor Rick Scott, stated that her office, not a grand jury, would decide whether to press charges in the shooting death of Martin. Angela Corey stated that, "I always lean towards moving forward without needing the grand jury in a case like this, I foresee us being able to make a decision, and move on it on our own."^[80] Florida Attorney General Pam Bondi said that the Florida Department of Law Enforcement (FDLE) was involved and "no stone will be left unturned in this investigation."^[167]

Medical records and autopsy[link]

On May 15, 2012 ABC News reported that a medical report compiled by the family physician of George Zimmerman showed that, following the alleged altercation with Martin, Zimmerman was diagnosed with a closed fracture of his nose, two black eyes, lacerations to the back of his head, a minor back injury, and bruising in his upper lip and cheek. According to the report, prior to the shooting Zimmerman had been prescribed Adderall and Temazepam. ^[169]

Martin's autopsy report was also released in May 2012.^[170] The examiner found the cause of death was a single gunshot wound of the chest, classifying the manner of death as "homicide". There were perforations of the heart and one lung, collapse of both lungs, and hemorrhaging in the pleural cavity. The examiner considered the bullet to have been fired "directly, front to back". There was no exit wound.

In looking at the entrance wound, the examiner assessed the gunshot as one fired from "intermediate range", which can mean from 1 to 18 inches, according to a forensics expert.^[171] The examiner noted "soot, ring abrasion, and a 2 x 2 inch area of stippling".

Besides the fatal gunshot wound, the examiner also noted a "1/4 by 1/8 inch small abrasion on the left fourth finger".

The autopsy report stated that Martin had trace levels of THC, the active ingredient in marijuana, in his blood and urine.^[172][173] The toxicology report found the levels to be 1.5 nanograms/ml of THC and 7.3 nanograms/ml of THC-COOH, a metabolite of THC that can stay in the system for weeks after cannabis has been smoked.^[172][173] Larry Kobilinsky, a professor of forensic science stated that the THC amount was so low that it may have been ingested days earlier and played no role in Martin's behavior. "This kind of level can be seen days after somebody smokes".^[174]

Federal investigation[link]

On March 20, 2012, the Justice Department announced that it was opening investigations into the incident.^[175] The state governor, Rick Scott, has asked the Florida Department of Law Enforcement to investigate the shooting.^[176][177]

President Barack Obama, speaking to reporters on March 23 after federal investigators were deployed to Sanford, said, "When I think about this boy, I think about my own kids, and I think every parent in America should be able to understand why it is absolutely imperative that we investigate every aspect of this," and, "If I had a son, he would look like Trayvon."^[178]

The FBI opened a parallel investigation into whether Martin's civil rights were violated, and interviewed witnesses and looked into Zimmerman's background.^[179]

Court proceedings[link]