Gardaí investigating the shooting dead of a Dublin criminal in the city are investigating whether dissident Republicans were involved in the murder.
Christopher Zambra was a suspected killer and drugs dealer. Along with several underworld colleagues, he had become embroiled in feuding with Dublin-based dissidents.
Calling themselves the Real IRA and under the leadership of the late Alan Ryan of Donaghmede in north Dublin, the paramilitary faction was extorting money for several years from drugs and robbery gangs across the city.
The gangs then formed a coalition of sorts in an effort to take on Ryan and his associates and an entrenched feud ensued in which guns and explosives devices were used.
In September 2012 the fighting escalated significantly when 32-year-old Ryan was shot dead as he walked along the street in Clongriffin, north Dublin.
A fellow member of the Real IRA at the time, Belfast man Declan Smyth was one of the first people on the scene in the minutes after the fatal attack on Ryan. He died in March, a week after being shot and wounded outside a crèche in Donaghmede.
Gardaí believed a north Dublin gang leader was one of a number of key people who planned and paid for the murder of Ryan. Zambra, who was shot dead in his native Drimnagh in south Dublin on Sunday afternoon, was regarded as being very close to that criminal.
Zambra (38), Galtymore Rd, Drimnagh, was ambushed on Cooley Rd at 3pm when two vehicles blocked his car at the front and rear as he was driving to visit a family member.
A large number of bullets were fired at him while he was still in his Audi car and then also as he tried to flee. He collapsed outside a house and died.
A Nissan Qashqai used in the attack was found on fire on Bedmadigan Rd close by with a handgun inside which is believed to have been the murder weapon.
Zambra's was the eighth gun murder of the year. He was acquitted last June of the murder in February 2009 of drugs importer John Carroll who was shot dead as he socialised in Grumpy Jacks pub in the Coombe.
It was the second time he had gone on trial for the killing, with a jury failing to agree a verdict two years earlier.