GARDAI are working on the theory that a 46-year-old man who was battered to death was not the victim of a random attack and knew his killer.
Anthony Fallon from Clonmel, Co Tipperary, was found lying in the stairwell of an apartment complex a short distance from his home at 6.45am.
Sources say that he suffered "horrendous multiple" injuries and Mr Fallon had been beaten over the head with a heavy instrument.
Gardai believed the attack is linked to a personal row.
One line of inquiry is that Mr Fallon was assaulted in his flat on Abbey Street and his body moved to the stairwell.
This would have involved the victim's lifeless body being dragged for hundreds of metres.
"Gardai are satisfied that this was not a random attack -- they believe that this man knew who attacked him," said a source.
Officers are also probing reports that Mr Fallon had been injured in a separate attack in the town over Christmas.
His grief-stricken widow Elma Molloy, from whom he was separated, said that Anthony was a "gentleman" and that they were "still friends".
"We are waiting to hear what happened from the guards. I'm very upset," she added.