Important evidence cited against Ken Barrett came as a result of covert operations organised by detectives working for the Stevens inquiries.
When Sir John Stevens launched his third inquiry in 1999, Barrett was arrested and interviewed about a number of murders, including that of the lawyer.
The court heard that Barrett had agreed in the summer of 2001 to meet members of a BBC Panorama team in the car-park of an exclusive north Down hotel.
For a £300 fee, he agreed to meet reporter John Ware and his editor for a meeting which was secretly filmed.
Barrett told them of the role played by some RUC officers in some loyalist murders, including that of Pat Finucane.
He claimed that the murder was initiated by them and, in co-operation with another agent Brian Nelson, he was encouraged to target the solicitor.
The court heard that Mr Finucane's killers were given confirmation of the victim's presence at his home and details of security force checkpoints in Belfast so they could avoid them.
The Panorama programme was broadcast in June 2002 by which time Barrett had been whisked out of Belfast by the police and was in England.
It was here, the court heard, that Barrett was pressed by his partner to get a job. The Stevens team saw this as an opportunity to set up a "sting" operation. They established a bogus limousine hire company which advertised for a driver.
When the suspect eventually applied for the position he was offered a driver's job and worked alongside two others known to him as Tom and Steve.
However these were both undercover officers working for Sir John Stevens.
Believing the two men to be involved in drugs, Barrett gradually revealed he was an experienced criminal and admitted the "whacking" of Pat Finucane and others.
"That was my way of life at the time." Asked how he slept at night, Barrett replied: "I sleep fine. . . it never worried me before."
He said he did not want his children to know of his involvement and said: "As far as I am concerned, it's finished.
"It's done. He's dead and buried. The others are dead and buried."
Barrett, the court heard, said the Finucane shooting was not the first occasion in which he was involved and he added: "He thought he could not be touched . . . he got . . . massacred 22 times. I lost no sleep over it . . . all is fair in love and war."
Barrett said his adrenaline was running when he shot Mr Finucane.
Mrs Finucane, he said, was shot in the leg "because she was making a fuss".
Speaking after the court proceedings Cmdr Dave Cox, now day-to-day head of the Stevens team, defended their sting operation and claimed it was necessary and legal.