The Garda Commissioner has said no one underestimates how difficult it will be to bring the killers of Det Garda Adrian Donovan to justice.
Garda Commissioner Martin Callinan said steady progress was being made in the murder investigation, which he revealed would be slow and painstaking.
He maintained he was optimistic that those responsible would be brought before the courts.
"No one, including myself, is underestimating how difficult that process will be," said the commissioner. "But we have very good people working on the case. Very committed and dedicated people."
Thousands of gardaí yesterday joined mourners at the funeral of the detective, who was killed as he confronted a gang of men on rural roads near his home on the Cooley peninsula near the border last Friday night.
Mr Callinan gave a reassurance that no stone will be left unturned in trying to bring Det Garda Donohoe's killers to justice.
The 41-year-old was shot in the head as he approached a five-man gang at a car in the grounds of his local credit union in the village of Lordship.
An 08-D navy Volkswagen Passat - stolen from Clogherhead in Co Louth on January 22nd and used in the attack on Friday night - was later being found burnt out beside a forest in south Armagh.
"All of the resources that the state can deploy at the moment are being utilised in this investigation," said the commissioner. "All of the national units and all of the specialist units are assisting the local gardaí, who are doing a tremendous job of work up there in pulling those details together. And that work will continue unabated and resources will not be an issue. They will be there as long they are necessary."
The Garda chief appealed for gardaí and the PSNI to be given the space to catch the killers, adding that it would be dangerous for them to reveal information on suspects or investigation tactics.
Minister for Justice Alan Shatter issued a fresh appeal for information. "There are husbands, wives, sons, daughters, neighbours, friends, who must know the individuals engaged in this," said Mr Shatter. "They are not five people operating in a vacuum."
Mr Shatter said Det Garda Donohoe lost his life standing up for the bond between the community and gardaí.
"I hope that the great outpouring of support which we have seen right across the country will provide some measure of comfort to Adrian's family," said Mr Shatter. "Our priority is to see the evil killers brought to justice but I know we are all determined more than ever to make sure that special bond between the gardaí and the community remains at the heart of policing in this country."
PA