He was was shot during a robbery in Co Louth
Gardaí say they will not stop until those responsible for the murder of Detective Garda Adrian Donohoe are brought to justice.
Today marks five years since the 41-year-old father of two was shot during a robbery at Lordship Credit Union in Co Louth.
Gardaí say the suspects are known to them and some of them are still living in the country.
However no one has been arrested or charged with Detective Donohoe's murder.
He was the 87th member of the force to be killed in the line of duty.
Chief Superintendent Christopher Mangan made this appeal directly to them and their families.
"The persons involved in this murder have no doubt received logistical and emotional support from their families and friends.
"I am speaking you you in particular, the families and friends of these people who were involved in this murder: your mind will never have peace until you tell the truth of what happened to Adrian.
"It's not too late to do the right thing".