Operation Flavius was the name given to an operation by a Special Air Service (SAS) team in Gibraltar on 6 March 1988 tasked with preventing a Provisional Irish Republican Army (IRA) bomb plot. The IRA Active Service Unit's (ASU) members, Danny McCann, Seán Savage and Mairéad Farrell, conspired to detonate a car bomb where a military band assembled for the weekly changing of the guard at the governor's residence. Although the operation was meant to be an arrest operation, it ended with all three members of the ASU dead.

Bomb plot:
The IRA members planned to hide the bomb in a car to kill the band members of the Royal Anglian Regiment that would assemble for the parade. To ensure a parking space in the busy town area, it was necessary to occupy it on the preceding Sunday.

The SAS team was informed - incorrectly - that the IRA had already placed their bomb and were ready to detonate it. The three conspirators were stopped as they walked near the Shell filling station in Winston Churchill Avenue, the busy main road leading to the airport and the frontier with Spain. McCann was then shot as the SAS claimed he made an 'aggressive move' towards a bag he was carrying. They stated that he was intending to trigger a car bomb using a remote control device. After McCann was killed, it was claimed that Farrell made a move towards her handbag and was shot on similar grounds. SAS members again claimed that Savage moved his hand to his pocket and the SAS killed him also.

McCann was shot five times, Farrell eight times, and Savage between 16 and 18 times. All three were subsequently found to be unarmed, and without any kind of remote trigger. Materials for a bomb, including 64 kg of Semtex, were later found by the Spanish police in a car in Marbella, 46 miles away in Spain, identified by keys found in Farrell's handbag.

Milltown Cemetery attack:

Ten days later, at the funeral of the three killed in the operation, a Ulster Defence Association (UDA) loyalist gunman (Michael Stone) went into the cemetery and shot dead three people and injured dozens with grenades.

Death on the Rock:

The following month ITV broadcast a Thames Television documentary "Death on the Rock" reflecting concerns about the shootings, which led to criticism of the British government. British tabloids attacked the character and credibility of some of the witnesses in an attempt to discredit their statements, which eventually led to successful libel actions by Mrs. Carmen Proetta against several newspapers, including The Sun and The Sunday Times.

Reviewing this documentary The New York Times (13 June 1989) stated: "Events leading up to the Gibraltar killings are depicted in a reconstruction made for a British television documentary. Questions abound. Was the IRA trio, carefully followed for days, in fact lured into Gibraltar? Why did the police fail to photograph the bodies or gather forensic evidence? Why was the press-Britain's tabloids were jubilant-told lies about a huge car bomb being defused and about the three suspects having died in a gunfight? This documentary's understated observation: 'There was a strong air of Government cover-up and disinformation.'"

British Prime Minister Margaret Thatcher denounced the documentary as "trial by television".

IRA response:

On 18 September 1990 the IRA attempted to kill Air Chief Marshal Sir Peter Terry at his Staffordshire home in revenge for his part in Operation Flavius. Terry had been Governor of Gibraltar during the Operation and had authorised the SAS to pursue IRA members. The attack took place at 9 pm at the Main Road house. The gunman opened fire through a window hitting him at least nine times and injuring his wife Betty, Lady Terry, near the eye. The couple's daughter, Liz, was found suffering from shock. Terry's face had to be rebuilt as the shots shattered his face and two high-velocity bullets lodged a fraction of an inch from his brain. Margaret Thatcher later said that she "was utterly appalled and deeply grieved" by the shooting.

Inquest:

An inquest was held in Gibraltar. An Irish radio expert disputed whether a remote-controlled explosive device was technically feasible with then-current technology, casting doubt on the justification given. This was further disputed at the European Court of Human Rights.

Captain Edwards, a member of the Royal Corps of Signals with experience in VHF/HF radio in combat net radio spectrum carried out tests which showed it was possible to receive both voice communication and a single audio tone at the site of the shootings from the assembly area.

The car bomb found in Marbella was a conventional timer controlled device. An article after the inquest in the magazine Wireless World proved mathematically that it was theoretically possible for it to be radio controlled.

The jury at the inquest returned a verdict of lawful killing by a 9-2 majority.

European Court of Human Rights:

In 1995, the European Court of Human Rights ruled by a majority verdict ten votes to nine that: "the Court is not persuaded that the killing of the three terrorists constituted the use of force which was no more than absolutely necessary in defence of persons from unlawful violence within the meaning of Article 2 para. 2 (a) (art. 2-2-a) of the Convention."

Therefore there had been a breach of the above article of the European Convention on Human Rights in relation to the deprivation of life.

It also ruled that the three had been engaged in an act of terrorism, and consequently dismissed unanimously the applicants' claims for damages, for costs and expenses incurred in the Gibraltar Inquest and the remainder of the claims for just satisfaction.

In February 2008, the Irish media carried reports alleging the Garda (Irish police) had passed on information about the three's movements to the British security services prior to their departure to Gibraltar.

Examination of MI5 records:

Professor Christopher Andrew, the official historian for the Security Service, was given access to MI5's records to prepare a book for the centenary of the organisation. Andrew said he was "confident" that there was no shoot to kill policy in operation and that MI5 had made a mistake in assuming that McCann, Savage and Farrell were carrying a means of causing an explosion when shot.

The book also contains a surveillance photo of Siobhán O'Hanlon taken in Gibraltar prior to the shootings, and a map of her movements. The files state that she noticed Spanish intelligence following her in Spain and returned to Ireland. O'Hanlon was a Sinn Féin official and an aide to Gerry Adams. Some British newspapers have accused her of being involved in the attempted bombing in the past. She died in 2006.

Andrew had access to all files created by MI5 since it was founded but was limited in what he could publish. He was required to enroll in the Security Service in order to be given access to the archives, which drew criticism from some historians and commentators prior to the writing of the book. In general, these criticisms suggested that he was too close to MI5 to be impartial, and that his link with the Service made him a "court historian" instead of a clear-eyed and critical historian. The First Post has claimed that Andrew was "MI5's main recruiter in Cambridge".