Gardaí are on high alert after a chief suspect in the Adrian Donohoe murder investigation was released from prison.
The Herald has learned that the dangerous criminal, aged in his early 30s, walked out of a Dublin jail last Thursday after being held behind bars for several months.
The cross-Border thug is suspected of being a key member of the gang behind the Lordship Credit Union robbery in Co Louth during which Det-Gda Donohoe was shot dead seven years ago.
Last month, Aaron Brady (29) was found guilty of capital murder and will face a mandatory 40-year prison term when he is sentenced next month.
Gardaí are continuing their inquiries into the hero detective's murder and are hopeful of bringing further charges against other gang members involved.
One of these is Suspect B, who was named during the murder trial as being centrally involved in the robbery.
The thug was on bail at the time of the murder and only months before had directly threatened Det-Gda Donohoe after being arrested by him.
The criminal has also been linked to a spate of high-profile ATM raids in recent years in highly organised raids. He was jailed in the capital for several months over an incident unrelated to the detective's murder, and was released last week.
A source told the Herald: "He is considered to be a particularly dangerous individual and there is a real concern that he will become actively engaged in criminality after his release.
"Investigations into him are ongoing in relation to the murder of Adrian Donohoe, and also in relation to ATM raids on both sides of the Border.
"Both gardaí and the PSNI will be keeping a close eye on him to prevent him linking up with his criminal associates and causing more havoc."
The Northern Irish man is suspected of being one of the masked raiders at Lordship Credit Union when Det-Gda Donohoe was shot dead on January 25, 2013.
He has also been linked to the theft of the getaway car, which was stolen three nights earlier from a house in Clogherhead, Co Louth.
The PSNI have interviewed him about his movements on the day of the murder but he has not yet been formally arrested as part of the murder inquiry.
Even before the raid he was well-known to gardaí for involvement in serious crime.
He had been arrested by Det-Gda Donohoe for the previous armed robbery at Lordship Credit Union in August 2011, as well as a separate armed raid at Dundalk racecourse that same year.
During his arrest he made a sinister threat to Det-Gda Donohoe, saying he knew where the detective's family home was located.
Since the fatal shooting, gardaí have identified 204 persons of interest in the case, and that list has been whittled down to just over 20 people.
This includes men and women who helped the killers as well as relatives and associates with information who are not co-operating with gardaí.
Five men remain formal suspects in the inquiry, including a father and his two sons, as well as a man centrally linked to diesel-laundering.
Aaron Brady, who was found guilty by the majority verdict of a 12-person of capital murder on August 12.
He is due to be sentenced on October 14.