The man who "danced on" Robert O'Connor's body after a vicious beating has claimed full responsibility for the murder, the Irish Mirror can reveal.
The thug, who repeatedly stamped on O'Connor's head in a Mountjoy prison cell last summer, is attempting to take the rap - despite three other lags' involvement in the killing too.
The criminal aged in his late 30s made the admission to gardai after he was arrested in jail and questioned.
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O'Connor was brutally beaten and kicked in a cell on Mountjoy's C2 landing by four men in an attack which lasted just seconds on Friday, July 29 last year.
The 34-year-old, who was found with his trousers around his ankles following the incident, was rushed to the Mater Hospital across the road but was pronounced dead the following week having suffered a severe bleed on the brain.
Four suspects were quickly identified and isolated before they were arrested and quizzed.
But only the man who stamped on O'Connor has made admissions and is attempting to take the full rap.
Gardai are now trying to establish why as they follow a number of lines of inquiry.
One theory is that the man - a former drug addict already serving a lengthy sentence - has received a payment as part of a deal in a bid to take the heat off other suspects. Another is that he may have been cleared of any drug debt he had on the outside.
A source said: "It's simply not known at this stage why he has made this move but no doubt he has his own motivations for doing so.
"The individual stamped on O'Connor's head repeatedly and danced on him in celebration before leaving the cell.
"But it's clear that this development doesn't absolve the others who are suspected to be involved in the murder."
Others suspects in the case who have been quizzed include a suspected Kinahan gunman, serving a sentence for his role in a botched hit, and another man who is caged for aggravated burglary.
All four suspects were seen leaving the scene of the attack and entering a separate cell where they changed their clothes before emerging and walking around the prison as if "nothing had happened," sources said.
It's also understood that gardai have established that a senior Kinahan cartel member sanctioned the attack on O'Connor.
The motive for the fatal attack on O'Connor came after his female associate was attacked outside of prisons months beforehand.
Sources said that O'Connor subsequently ordered an attack on a fellow lag over that incident.
As part of the major inquiry, investigators are also probing an incident on O'Connor two days before the fatal attack in which he was hit with a kettle over the head.
It happened on Mountjoy prison's D wing, and despite O'Connor refusing medical attention he was moved to the C wing for his own safety.
O’Connor, of Snowdrop Walk, Darndale, Dublin 17, was in jail for firearms offences and had previous convictions including drugs, stealing cars, criminal damage, theft and road traffic offences.
At his funeral, O'Connor's father Leo pleaded that there be no retaliation for the murder.
He said: "I would hate to see any retaliation. I'm begging anyone if they hear anything to do something to stop it."
An Irish Prison service investigation is also taking place in tandem with the garda probe, which is taking priority.
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