A plea bargain (also plea agreement, plea deal or copping a plea) is an agreement in a criminal case between the prosecutor and defendant whereby the defendant agrees to plead guilty to a particular charge in return for some concession from the prosecutor. This may mean that the defendant will plead guilty to a less serious charge, or to one of several charges, in return for the dismissal of other charges; or it may mean that the defendant will plead guilty to the original criminal charge in return for a more lenient sentence.

A plea bargain allows both parties to avoid a lengthy criminal trial and may allow criminal defendants to avoid the risk of conviction at trial on a more serious charge. For example, a criminal defendant charged with a felony theft charge, the conviction of which would require imprisonment in state prison, may be offered the opportunity to plead guilty to a misdemeanor theft charge, which may not carry jail time.

In cases such as an automobile collision when there is a potential for civil liability against the defendant, the defendant may agree to plead no contest or "guilty with a civil reservation", which essentially is a guilty plea without admitting civil liability.

Madeleine McCann disappeared on the evening of Thursday, 3 May 2007. She was on holiday with her parents and twin siblings in the Algarve region of Portugal. The British girl went missing from an apartment, in the central area of the resort of Praia da Luz, a few days before her fourth birthday, and has still not been found. Madeleine's parents, Kate and Gerry McCann, have said that they left the children unsupervised in a ground floor bedroom while they ate at a restaurant about 120 metres (130 yards) away.

The initial investigation by the Polícia Judiciária (PJ), the Portuguese criminal investigation police, was based on the assumption that the child had been abducted. After further investigation, the PJ stated that there was a strong hypothesis that she might have died in her room. During the investigation there were a number of unconfirmed sightings of Madeleine in Portugal and elsewhere, and additional scientific evidence was obtained. The investigation involved the co-operation of the British and Portuguese police and demonstrated the differing methodologies employed by each, with regard to such aspects as the amount of information released to the public and the legal status of those involved in the case.