A FORMER soldier and arms expert joined one of the country's most dangerous crime gangs after he left the Army.
Warren has been jailed for 11 years for his role in the attempted robbery of almost €900,000 from a cash-in-transit van five years ago.
He was the sixth and final gang member to be sentenced for attempting to rob €880,000 from a security van at Tesco in Celbridge, Co Kildare.
Passing sentence, Circuit Criminal Court judge Patrick McCartan commended members of the gardai for "the professional and effective way they pursued Warren and associates" – a gang he described as being involved in drug dealing, armed robbery and "contract killings as necessary".
Warren, of Belclare Crescent, Ballymun, Dublin, denied conspiring to steal cash from Chubb Ireland at Tesco supermarket on the Shackleton Road in Celbridge on November 2, 2007, but was convicted of the charge by a Dublin Circuit Criminal Court jury last week following a three-week trial.
The qualified bricklayer pleaded guilty earlier this year to possession of ammunition at Poppintree Park, Ballymun, on July 19, 2009.
The gang, including Eamon Dunne, Alan and Wayne Bradley, Jeffrey Morrow, Michael Ryan and Warren, had followed a Chubb Ireland Nissan Patrol vehicle for a number of hours in the hope of stealing over €880,000 from the safe.
Warren was arrested in the Tesco carpark that morning after he was observed by gardai approaching the vehicle with a running concrete saw. Ryan had just tried unsuccessfully to open both the passenger and driver doors.
The other men were arrested in the vicinity, as was Chubb worker Daryl Caffrey who had been the passenger in the Nissan Patrol that day.
He was considered "the inside man" and had provided information to the gang, the court was told.
Warren claimed he was acting under duress from Dunne and was told that he would be going to "God's house" if he didn't open the vehicle.
The garda investigation, led by Detective Superintendent Dominic Hayes, involved months of surveillance prior to the attempted heist and included members from the National Bureau of Criminal Investigation, the Special Detective Unit and the Crime and Investigation Unit.
"They (the gardai) have done the community a good service," Judge McCartan said, before adding that each of the members of the gang had received their just deserts.
He said it may seem wrong to make such a comment about the deceased Dunne but added: "He who rules by the sword may end up done by the sword."
Warren told the court he believed Deirdre Murphy, prosecuting, was right when she suggested to him during the trial he was attracted to Dunne's gang having experienced the "camaraderie" of the army.
He told his counsel Ciaran O'Loughlin, however, that he never "really fitted in". Warren reassured Judge McCartan that he had now "got that out of my system" and apologised to his family, his friends and his partner for bringing shame upon himself and his family.
The court heard that 193 phone calls were exchanged between all six men that day.
Judge McCartan sentenced Warren to eight years for the conspiracy charge and a consecutive term of six years for the possession of ammunition charge before he suspended the final three years. The judge said he was moved by a letter from Warren's partner, Jennifer Hyland, and how he had cared for her and her two children.
He said he had also taken into account a letter from Warren's mother and his brother about how they were ashamed and stunned by his behaviour.