THE execution of RIRA member Peter Butterly is the first murder in an internal feud which threatens to plunge dissident republicans into an all-out civil war.
Gardai have several well-placed informants planted in the various IRA factions and know that Butterly's shooting was ordered by a so-called disciplinary squad.
The squad was set up to purge the ranks of the Real IRA of "undesirable elements" with obvious connections to organised crime. The deadly initiative begun after the disparate republican gangs decided to merge in a new alliance simply calling itself the "IRA".
The group includes the Real IRA, Republican Action Against Drugs (RAAD) and Oglaigh Na hEireanni. Senior security sources are concerned that the new IRA also includes a hard-core group of veteran Provos who had previously stayed in the background.
Police on both sides of the Border fear that the involvement of the older IRA members will bring a greater level of organisation to the dissident republican rabble.
Their goal is to plunge Ireland back into the dark days of the Troubles. And like the Provos before them, they are funding their grand plan through organised crime – extortion, smuggling, oil laundering, drugs and robbery.
They set to work in the immediate aftermath of the murder of RIRA boss Alan Ryan who they first turned into a martyr for the cause before moving against his closest associates.
Many believe that if he hadn't been taken out by a drug gang he had been feuding with, Ryan would probably have been executed by the same people responsible for yesterday's killing.
Within weeks of Ryan's demise the internal squad began interrogating RIRA members about drug trafficking and the misappropriation of money extorted from criminals.
Last November, Nathan Kinsella, who is currently charged with RIRA membership, was shot in the legs.
In January, the IRA told a newspaper that they were responsible for Kinsella's shooting and also pointedly stated that Ryan's second in command, Declan 'Fat Deccie' Smith, was also a marked man. A week later he was "interviewed" by the discipline squad and shot in the legs.
Last month the Irish Independent revealed that the punishment shootings had taken place after money, which was being paid to the organisation by a high-profile businessman, did not make it to the RIRA's war chest.
The businessman, who has been secretly involved in organised crime for decades, has agreed to "donate" over €1m to the cause this year in return for protection from other criminals.
The situation that is developing among the ranks of the dissidents is reminiscent of the feuding that tore the INLA and the IPLO apart in the late 1980s, which gave them the distinction of murdering more of their own comrades than the hated enemy – the British Army.
But the new IRA is facing a more serious threat from their old adversary – the Garda Special Branch, which has riddled the organisation with highly-placed informants.
The information which led to the PSNI foiling a mortar attack in Derry on Sunday came from the Special Detective Unit, colloquially known here as Special Branch.
The van-mounted mortars are more sophisticated than anything else produced by the dissident gangs. The appearance of such devices has not been seen since the Provos announced their ceasefire and security sources say it is further evidence of the involvement of the veteran IRA men.
Last November the new-look IRA suffered another major setback at the hands of the gardai when four men were arrested following the murder of veteran gangland boss Eamon Kelly in Dublin.
A man later gave detectives detailed information about who organised the high-profile hit and who took part in it.
The arrest of four men within a minute of the Butterly murder yesterday is further proof that the gardai have a well-established source of intelligence on their activities.
The ERU team and the National Surveillance Unit are understood to have been in the area after receiving a tip-off that a number of senior figures were planning to meet at the Huntsman pub, Gormanston.
However, the murder was unexpected and as soon as it went down, the ERU moved in and arrested the four men, all of whom are well-known dissident gang members.
Inevitably the dead man's cronies will claim he was set up by the police: the Real IRA made the same claims after Ryan was murdered. But the truth is the only people doing the setting up of murder targets are the republicans themselves.