Patrick Thompson received a life sentence with a 30-year minimum term for the murder of four British Army officers in a landmine attack early in the morning of 17 July 1975 on the road between Dundalk and Newtownhamilton.

Just before the explosion, a solder using the optical sight of his rifle had spotted a man running from the scene. Mr Thompson was stopped by the Army around 15 minutes after the explosion on the basis that he matched the soldier’s description and arrested.

Mr Thompson was interviewed five times without a solicitor present. After denying responsibility in the first three interviews, he gave a verbal account of his supposed involvement in the attack in the fourth interview and then signed a statement.

After the fifth interview, Mr Thompson collapsed in pain and made a complaint of assault against the police. He was subsequently examined by three separate medical professionals who reached diverging conclusions.

In a Crown Court trial in 1976, the allegation of ill-treatment was raised but the trial judge deemed the confession admissible.

Mr Thompson was found guilty of four counts of murder and one count of membership of a proscribed organisation, receiving a life sentence for the first four counts, with 30 years as the minimum period, and five years on count five.

He appealed later that year, alleging bias in the conduct of the trial as the judge failed to exclude the confession evidence, obtained as a result of ill treatment and failed to give adequate consideration to the medical evidence. The appeal was dismissed in 1977 and Mr Thompson remained in prison until his release in 1992.

He lodged an application with the CCRC in February 2018, which was referred to the Court of Appeal in March 2022.

The CCRC referred Mr Thompson’s case on the grounds that there was a real possibility the Court of Appeal would find his conviction to be unsafe because the senior officer who led the investigation was not a credible witness.

The same police officer had been criticised in the Court of Appeal’s decision in R v Latimer, Hegan, Bell and Allen [1992] 1 NIJB 89, in which three appellants had their convictions quashed on the basis that he and another officer appeared to have appended false authentications which had been backdated by five days to some of the interview notes.

The Lady Chief Justice, Dame Siobhan Keegan, referred to this when quashing the conviction and said: “We also commend the CCRC for drawing the Latimer issue to the attention of the court.”

In her judgment, she continued:

Accordingly, the court could not be satisfied as to the safety of the convictions and therefore quashed the convictions.