The 'scandal' of Scotland's longest gangland trial
When Paul Ferris was cleared of the gangland murder of crime boss Arthur Thompson Jnr in 1992 it came after what had been the longest and most costly trial in Scottish criminal history.
The cost of the court case was put at £4m and more than 300 witnesses were called to give evidence during the 54-day trial.
But journalist and crime writer Douglas Skelton tells the BBC's The Scandals that Shocked Scotland there were so many people telling lies that it was difficult to get through to the truth. And the evidence of the main prosecution witness was so flawed the jury had no choice but to acquit.
"To have a trial of that length, to cost that amount of money and to have the evidence being presented being so weak, I think the only word you can use is scandal," he says.
No-one has ever been found guilty of the gangland killing of the eldest son of the godfather of Glasgow's biggest criminal clan outside his home in 1991.
"Arthur Thompson was very much the old guard," says Mr Skelton. "He'd come up in the 1940s and 50s. He was a friend of the Krays in London. He was very much the old-style kind of Glasgow criminal."
Paul Ferris was a young man who had built a fearsome reputation that attracted the attention of Thompson.
According to BBC investigative journalist Sam Poling: "Paul Ferris was a well-known criminal. A violent man by his own admission. You have got to remember this man was feared around the country."
In the early 80s, Ferris became part of Arthur Thompson's gang and was known as an enforcer, someone who would threaten and, when necessary, mete out the violence.
Thompson's eldest son, Arthur Jnr, also known as "Fat Boy", was just a few years older than Ferris. He was rising up the ranks to take over from his father but didn't command the respect that Arthur Snr had.
Ferris and Fat Boy worked together in the business but they had a falling out, Mr Skelton says.
"Paul Ferris blamed Arthur Thompson Jnr for essentially fitting him up on a charge which led to a conviction," he says.
In August 1991, Arthur Thompson Jnr, who was serving an 11-year sentence for possessing heroin with intent to supply, was home on leave.
He was shot three times while walking the short distance from his own house to his parents' home, which was two converted council houses in the city's Blackhill area, known as the Ponderosa.
Ferris was the prime suspect but two others were incriminated. His pals Joe Hanlon and Bobby Glover did not live to stand trial. On the day of Arthur Thompson Jnr's funeral, Glover and Hanlon were found dead in a car on the cortege route.
Paul Ferris, who was 28 at the time, was charged with murdering Thompson by shooting him in the head and body.
The trial began in March 1992.
Gang boss Arthur Thompson Snr was a key witness at the trial. The 61-year-old described himself as unemployed and said he had been claiming sickness benefit for two years.
Defence lawyer Donald Findlay said it might be suggested that Thompson orchestrated the killing of Hanlon and Glover in revenge for his son's death.
Thompson replied angrily: "I would say I was on trial here the way you are going." Looking at the dock, Thompson added: "That is the dock, this is the witness box."
The main prosecution witness in the trial also proved to be controversial.
According to Mr Skelton the main point of evidence was from a man called Dennis Woodman, a "supergrass" who had given testimony in five or six other trials in England.
Woodman claimed he had been in a segregation unit in Barlinnie Prison with Ferris, who had confessed to the killing.
"They are in separate cells," Mr Skelton said. "They can't see each other. They can't see outside. But according to the testimony, during this period of time, Paul Ferris confessed to killing Arthur Thompson Jnr.
"Paul Ferris was an experienced guy. I cannot believe that somebody like him would confess to a complete stranger who he can't even see, by shouting out to him, without knowing who is standing outside his door, listening or recording what is being said."
According to Mr Skelton, much of the other evidence had the jury scratching their heads. The trial was peppered with lies and half-truths, he says.
After 24 hours of deliberation, the jury acquitted Ferris of the murder and all other charges. On the steps of the court, he declared himself vindicated.
Mr Skelton says: "I think they reached the correct decision because the evidence just wasn't there. If they really believed that Paul Ferris was guilty of murder then they should have got better evidence than they did."
It is nearly 30 years since Arthur Thompson Jnr was shot and his murder case remains unsolved.
In 1998 Paul Ferris was sentenced to seven years for gun-running. He says he has now turned his back on a life of crime.