Anthony Mitchell, 45, who on Tuesday pleaded guilty to five counts of illegal firearms dealing and possession, has been linked with the seizure of 130 guns from crime scenes. They had been used for murders, shootings against police officers and in gang wars.
For years Mitchell churned out firearms at his workshop in an industrial estate in Hove, East Sussex. Almost all the dozens - possibly hundreds - of guns he supplied were supposed to have been deactivated. That is, they had been disabled so that they could not be fired but were "ornaments" for enthusiasts. The inquiry that led to Mitchell's convictionalso found his interest in guns went further afield: he was in a group of impostors who travelled the world, pretending to be British police officers so that they could enter shooting competitions.
He first came to the attention of the former South East Regional Crime Squad - now the National Crime Squad - three years ago. He was first named as a firearms dealer after a joint police and MI5 operation in 1997 that caught Paul Ferris, a criminal with a reputation for extreme violence, buying guns from John Ackerman, another dealer, from a street in Islington, north London.
In an Opal Fruits box police found three US 9mm MAC-10 sub-machine-guns. A favourite weapon of US crack gangs, and known as "Big Macs", they can fire 1,200 rounds a minute. Police also found silencers, ammunition and detonators. Ackerman, later jailed for six years, turned informer and named Mitchell as the source of the guns.
He was arrested in July 1997 but freed him after a search at the Hove workshop failed to find illegal guns. But officers from the National Crime Squad, assisted by the Organised Crime Unit at Scotland Yard and Strathclyde Police, set up a surveillance operation and kept tabs on one of Mitchell's associates, who was found to have 2.7kg of plastic explosives, two shotguns and a sub-machine-gun at his home.
Mitchell used the fact that he did not have a criminal record to set himself up as a legitimate supplier of licensed firearms to gun clubs and collectors.
But his secret work brought in the real money. As an engineer he developed a technique to reactivate firearms that were supposed to be permanently out of action.
He obtained a ready supply of deactivated guns from shops and mail-order firms. His speciality, or trademark weapon, was the MAC-10, which he reactivated by fitting a new barrel and breech block.
Police tests identified more than 100 MAC-10s - seized in Liverpool, Manchester, Glasgow, London, and south-east England - as being supplied by Mitchell. As well as MAC-10s, which cost pounds 1,100 each including a silencer and 120 rounds, there were revolvers and pistols, costing pounds 400 to pounds 500.
One of the weapons is believed to have been used for a street murder in Brixton, south London, in April 1997. Another was fired by a youth in Manchester at police officers in the Moss Side district.
Others were found during raids on drug stronghouses in Manchester. Mitchell was rearrested in October 1997 and 50 MAC-10s were found at his workshop.
Police discovered during a search of his run-down terraced house in Brighton that their target shared his fascination for firearms with a group of gun groupies.
With up to 12 other men Mitchell was part of an SAS-style organisation known as the Black Shods, who dressed in black boiler-suits and webbing.
The men had fake police identification cards, which they used to travel the world, including the United States, Germany, the Netherlands and Belgium, entering police shooting competitions.
Videos and photographs were discovered of them competing for, and on occasions winning, trophies.
The police also discovered that Mitchell had been thrown out of the Sussex Police's volunteer uniformed Specials in 1993 after his gun connections came to light.
After Mitchell's guilty pleas at the Old Bailey in London on Tuesday he was remanded in custody and will be sentenced on 19 February, when he could be given a maximum jail term of 10 years.
Detective Constable Cliff Purvis, of the National Crime Squad, said: "Some of the weapons which bore the Mitchell `signature' mark have been used in killings and to fire at police.
"I'm sure he was one of the major contributors to illegal firearms in this country - he was a big fish, there's no question of that."