A leading Real IRA figure was shot in the head as he lay injured on a Dublin street yesterday afternoon.
The victim, 32-year-old Alan Ryan, was a senior dissident republican in the capital and he had built up a long list of enemies.
He had been under Garda Special Branch surveillance since he was first arrested by armed officers at a Real IRA training camp and arms bunker at Herbertstown, Stamullen, Co Meath, in October 1999 while only a teenager.
He was gunned down yesterday while walking with a friend on the quiet Grange Lodge Avenue, Clongriffin, on the northside of the capital, shortly after 3.30pm.
Two gunmen approached Ryan and his friend, Sligo man Alan Neilis, who is a member of the 32 County Sovereignty Movement, a dissident political grouping.
Both men were hit and fell to the ground as one of the attackers opened fire.
The gunman then walked up to Ryan as he lay on the road and shot him in the head.
Mr Neilis was injured in the legs. Both men were rushed to Beaumont hospital, where Ryan was pronounced dead shortly afterwards.
Mr Neilis later underwent treatment for leg wounds and his condition was described as serious.
The attackers, meanwhile, made their escape in a silver Volvo car, which was found burnt out shortly afterwards at the Hole in the Wall Road.
Both areas were immediately sealed off by gardai for a forensic examination.
Ryan became a senior figure in the Real IRA over the past decade and took charge of a group that was largely based around his home area of Donaghmede, where he lived at Grange Abbey Drive, although he also had an address in Co Carlow.
He became involved in faction fighting within the terrorist group and was involved in a serious dispute with the Real IRA's current leader in Dublin, a Cork man living in Tallaght.
But gardai believe his killers were likely to have been hired by one of the many crime gangs that had come into conflict with Ryan over the past few years.
Ryan ran a big extortion and intimidation racket, focusing on pubs, clubs and other premises around Dublin while he also sought to take a slice of the profits built up by crime gangs from drug-trafficking and robberies.
His group also raised funds through providing door security and bouncers for pubs and clubs, resulting in a number of shootings as they clashed with rival criminals.
Gardai are satisfied that over 90pc of the "fund-raising" carried out by the Donaghmede group ended up in their own pockets, with the rest handed over to the Real IRA.
The terrorist faction is also believed by gardai to have been responsible for the murder of Sean Winters, who was gunned down in Portmarnock, Co Dublin.
Ryan played a major role in demonstrations around Dublin city centre last year in protest against the visit of Queen Elizabeth of England.
But gardai regarded him mainly as a criminal who used his affiliation to the dissident republican group as a cover for his activities.
One senior anti-terrorist officer said last night: "Ryan had a list of enemies that would fill up a page of a newspaper.
"At some stage over the past few years, he managed to clash with most of the big crime gangs around the city while at the same time falling out with many of his former colleagues in the Real IRA", he added.
The group has four "commanders" based in Belfast, Derry, the Louth Armagh border and Dublin.
Last night, gardai appealed to anybody who spotted people acting suspiciously or driving around in a silver Volvo car, in the Grange Lodge or Hole in the Wall road areas to contact them at Coolock station at 01 6664200, or on the confidential line, at 1800 666111.