Enlarge By Steve Ruark, AP Two young men peer inside the Armed Forces Career Center, which was closed, in Catonsville, Md. on Dec. 8. A Baltimore man was charged with trying to detonate what he thought was a bomb at this military recruitment center. Mohamed Osman Mohamud AP  SUSPECTS A side-by-side look at the suspects arrested in recent FBI sting operations in Oregon and Maryland: Name Mohamed Osman Mohamud Antonio Martinez, also known as Muhammad Hussain Age 19 21 Nationality Naturalized U.S. citizen Naturalized U.S. citizen Alleged target Christmas tree lighting ceremony, Portland, Ore. Military recruitment station, Catonsville, Md. Arrested Nov. 26 Dec. 8 Charges Attempted use of a weapon of mass destruction Attempted murder of federal officers/employees; attempted use of a weapon of mass destruction Maximum punishment if convicted Life in prison Life in prison Source: U.S. Justice Department Antonio Martinez AP

In the midst of planning a spectacular car bomb attack on a military recruiting center in a Maryland suburb, the 21-year-old construction worker also known as Muhammad Hussain learned that the FBI had infiltrated the planning of a similar, but unrelated, attack in Portland, Ore., federal court documents allege.

The Portland sting operation resulted in the arrest of a Somali-born suspect on federal charges. Martinez worried that one of his new confederates in the Maryland scheme also might be a government agent, federal prosecutors and the FBI say in the court documents.

"Who is this brother?" Martinez demanded, according to a transcript filed in court documents. He was referring to the seemingly well-connected partner — the man with professed access to firearms and explosives who had joined the operation just days before. "I'm not falling for no b.s."

Martinez, charged last week with attempted murder and the attempted use of a weapon of mass destruction, had every reason to be suspicious. The "Afghani brother," court documents say, was indeed an undercover FBI agent whose intense courtship of the terror suspect reflected a key strategy in the government's effort to thwart new attacks against the United States.

When terrorist hijackers struck on Sept. 11, 2001, the federal government had few contacts among international terror informants and little intelligence about global terrorism. Now, government investigators increasingly are resorting to a controversial tactic that has netted alleged plotters in Dallas, Washington, D.C., New York and Chicago.

But the simultaneous, months-long operations in Portland and suburban Baltimore are raising new questions about whether the government is going too far in trying to identify potentially dangerous operatives, prompting a debate about whether investigators are entrapping suspects who lack the genuine desire or ability to carry out the plots. In both cases, government informants first identified the suspects on the Internet and then undercover agents engaged them in elaborate ruses culminating in the delivery of dummy bombs to their alleged targets.

Federal investigators have been deployed in complex undercover stings for decades to battle a host of traditional enemies, from the Mafia and drug dealers to gun traffickers and spies. Its application in terror inquiries, however, is a more common recent strategy as the FBI confronts a growing, homegrown terror movement.

"All of this seems very unusual," says Peter Fleury, an assistant federal public defender in Dallas.

Fleury says he had never encountered such tactics until this year, when he was appointed to help represent Hosam Smadi, 20, a Jordanian national snared in a plot to attack a downtown Dallas skyscraper with a bomb that, it turned out, was fake and had been assembled by the FBI.

"I had never seen it happen before," Fleury says of the FBI's extensive involvement. He says Smadi, ultimately sentenced to 24 years in prison, was a victim of entrapment.

"Left to his own devices, he wouldn't have been able to pose a danger to anybody," Fleury says.

Farhana Khera, executive director of the Muslim civil rights group Muslim Advocates, says the sting operations suggest the FBI could be wasting valuable resources on people who, without the FBI's planning and technical help, may be incapable of little more than spouting unpopular political rhetoric.

"Some of these cases look and feel like entrapment," Khera says. Entrapment occurs when police persuade a person to carry out a crime the suspect had no previous intention to commit.

"But for the government's role in these cases," she says, "the suspects may have been left with their own bravado. Law enforcement resources need to be focused on actual threats."

U.S. Attorney General Eric Holder defends the government's tactics, saying they have been "critical" in neutralizing criminals for years.

"I make no apologies for how the FBI agents handled their work," Holder told Khera's group last week. "Those who characterize the FBI's activities … as entrapment simply do not have their facts straight or do not have a full understanding of the law."

Was it entrapment?

The FBI's courtship of Mohamed Osman Mohamud in Portland — like that of Martinez in Baltimore — began online.

Government investigators intercepted a series of Mohamud's e-mails to undisclosed contacts in Pakistan from August to December 2009, federal prosecutors and the FBI say in court documents.

The suspicious electronic communications, which allegedly contained "coded language" discussing Mohamud's preparations for "violent jihad," ultimately launched an inquiry that, as described in a 36-page federal criminal complaint, reads in part like a movie script.

It also set in motion a widening national debate — accelerated by last week's arrest of Martinez in Baltimore —over whether the government pushed the suspects to do something they could not have done, and perhaps would not even have attempted, on their own.

"The question we'll be looking into is the question of entrapment," Steven Wax, chief federal public defender in Oregon, said after a hearing last month in which Mohamud pleaded not guilty to the attempted use of a weapon of mass destruction. "One of the issues that will be coming up is whether and how he was directed by government agents."

In all, undercover FBI agents met with Mohamud seven times from July 30 to Nov. 26, when he was arrested after attempting to detonate a dummy explosive near a crowded public square. The court documents describe contacts including:

•Undercover FBI agents, posing as eager jihadists with connections to Mohamud's contacts in Pakistan, arranged secret meetings at Portland-area hotels.

•There were discussions of possible targets before Mohamud settled on a Nov. 26 Christmas tree-lighting ceremony at the city's Pioneer Square.

•A Nov. 4 dry run, just three weeks before the designated attack date, displayed the bonafides of undercover agents who arranged for the assembly and the detonation of a test explosive in rural Lincoln County, Ore.

•Agents posing as jihadists after the test explosion also helped Mohamud — dressed in a white robe, head-dress and camouflage jacket — prepare a "Sheik Osama-style" video in which Mohamud allegedly recites a rambling statement taking responsibility for the planned attack.

The extensive contacts, Wax has argued, raises the prospect that the alleged action "was instigated by government agents."

"The government provided the money, the government provided the transportation, the government was involved in the meetings," Wax told reporters after last month's hearing.

The defense team also plans to delve into details surrounding the first meeting between Mohamud and the FBI — July 30 — when the suspect allegedly told an undercover agent that he wanted to become "operational but noted he did not know how and he would need training."

Unlike other meetings and contacts with Mohamud, the July 30 conversation was not recorded "due to technical problems," according to the court documents.

"There will be questions raised about that," Wax says.

But Portland FBI chief Arthur Balizan says in a statement that Mohamud was "absolutely committed to carrying out an attack on a very grand scale."

FBI agents offered Mohamud several chances to withdraw from the plot, the court documents say, and he pushed forward each time.

"I want whoever is attending that event to leave … either dead or injured," Mohamud allegedly told agents.

The FBI's lab

On the day Mohamud allegedly had selected to carry out the attack, he unknowingly was videotaped inspecting the handiwork of FBI technicians.

Stowed in the back of a white van were six 55-gallon drums, a coil of detonation cord, blasting caps and a gallon of "strong"-smelling diesel fuel, all arranged to look powerful vehicle bomb.

"Beautiful," Mohamud allegedly declared — just moments before he unsuccessfully tried to detonate the phony device and was placed in handcuffs.

The elaborate props, says Don Borelli, a former assistant agent-in-charge of the FBI's New York Division, often are integral parts of investigations that have targeted drug lords, spies and now, terrorists.

In the highly secretive espionage investigation of former FBI counterintelligence agent Robert Hanssen unmasked in 2001, for example, the FBI purchased a house across the street from the now-convicted spy's house in Vienna, Va., and had an agent posing as a neighbor conduct constant surveillance.

The deception was designed to catch Hanssen turning over classified government documents, but agents did not actually pose as Russian spies. Hanssen later pleaded guilty and was sentenced to life in prison.

In terror cases, Borelli says, the FBI's Quantico, Va., laboratory serves as a studio where inert bombs and other devices are designed and assembled. The design and study of bomb-making has been an intense focus of investigators, especially since U.S. troops increasingly began encountering improvised explosive devices in Iraq and Afghanistan.

"It's almost like a movie set," Borelli says. "They can manufacture anything."

Borelli says the deception does not constitute entrapment.

"We are getting more (terror) cases that avail themselves to this type of investigation," says the former counterterrorism agent, now vice president of a New York-based security firm.

He says federal prosecutors "like the technique" because the sting operations lend themselves to gathering potentially powerful audio and video evidence.

"We have to show in court absolutely that the intent of the subject was to follow through with the plan," Borelli says. "We want them to go through all the steps, dialing the cellphone or pulling the trigger. As we're doing so, we're giving these guys options to back out. It's not entrapment."

In New York Wednesday, Abdul Kadir was sentenced to life in prison for plotting to bomb JFK International Airport. Early in that sting operation, which also involved an FBI informant, Kadir's lawyers raised the prospect of entrapment.

The Center on Law and Security at New York University School of Law, which tracks federal terror prosecutions, reported in September that the entrapment defense has never been successful in a post 9/11 terror trial.

A 'grinning' suspect

In a Baltimore federal courtroom Monday, prosecutors again defended the tactics used by FBI agents in last week's arrest of Martinez.

The investigation began in September, after an FBI informant noticed a series of threatening postings on Martinez's Facebook account, according to federal court documents.

An FBI affidavit outlining the operation portrayed Martinez as so eager to lash out against the USA that he unsuccessfully sought to recruit three unidentified accomplices. He was arrested Dec. 8 after allegedly trying to detonate a fake car bomb outside the Catonsville, Md., recruiting station.

Assistant U.S. Attorney Christine Manuelian said video recorded throughout the investigation shows the suspect "grinning" as he armed a vehicle bomb to attack the suburban military recruitment center.

"There is no indication of any remorse, any concern … that he is about to kill people," Manuelian said before Martinez was ordered to jail pending trial.

Defense attorney Joseph Balter, like his counterpart in Portland, disagrees with the government's assessment.

He characterized the plot in Monday's court hearing as "the creation of the government."

"There was nothing provided," Balter said, "which showed that (Martinez) had any ability whatsoever to carry out any kind of plan."

Contributing: The Associated Press