All four suspects in the brutal Pearse Street murders remain in custody as gardai grill them on last Sunday's double gangland killing.
The prime suspect in the murder case and his girlfriend are still being detained along with two associates.
The four were brought in front of a special sitting of Dublin District Court on Tuesday night where they had their period of detention extended.
Under Section 50 of the Criminal Justice Act, a chief superintendent must give evidence to a judge warranting a suspect's continued detention, illustrating the gardai's determination to glean as much information from the four as they can.
They can have their periods of detention further extended on Friday if gardai see fit to make the application.
The prime suspect is well known in Dublin crime circles and is a known associate of the deadly gangster known as the "Don".
The crime boss is believed to be responsible for 12 murders in two years and has been described as a "psychopath" by gardai.
Brendan Molyneaux and his friend, Paddy Mooney, who had no gangland connections, were chatting in Paddy's flat when two gunmen burst in through the front door at 6.45pm last Sunday. Paddy was shot twice in the head by the gunmen in Pearse House, off Pearse Street.
Mr Molyneaux, his friend and the intended target, was shot once in the chest during the attack.
Mr Molyneaux had been targeted because of underworld intelligence that he had agreed to kill the man believed responsible for the murder of criminal Paul 'Farmer' Martin at the Jolly Toper pub in Church Street, Finglas, last August.
The target that Mr Molyneaux had been contracted to kill is believed to have been a high profile member of the the "Don's" gang.
The family of Paddy Mooney, the innocent victim of the gangland attack, have spoken of their sorrow of losing another beloved family member.
Their have been four tragic deaths in the family in the past two years.
Paddy Mooney's nephew, Leigh Mooney, died along with a friend two years ago when they drove their Fiat Punto down the wrong side of the N7 in Citywest and straight into an off-duty garda.
The same garda had been involved in a crash just three months previously which claimed the life of Leigh's cousin, Philip Hogarty.
It has also only been a matter of weeks since Eugene Bourke, Paddy Mooney's brother-in-law was buried.
Paddy's sister Margaret has spoken of the family's immense grief. "It's been heartbreaking" she said."We can't understand why someone would do that to Paddy, to do that to another human being. They must have no heart.
"Paddy was a real happy go lucky man," she added.
"He used to joke and call himself Robocop because of his limp."
Paddy Mooney's body has not been released to his family for burial.