GARDAI hunting the murderers of their colleague Adrian Donohoe are making steady progress, according to Commissioner Martin Callinan.
But he admitted that turning intelligence into evidence was a painstaking process.
"We will not rush this investigation but will use all of the available methodologies to bring the perpetrators to justice", he said. "It is important we are allowed some space to make our inquiries," he added.
He said the gardai were working closely with the PSNI, adding he was always optimistic about the outcome but was not under-estimating how difficult the process could be.
The commissioner pledged that the huge team currently deployed at Dundalk, including the national support units, specialist search teams and local officers, would stick at the task for as long as was deemed necessary.
Extensive inquiries are being carried out on both sides of the Border as officers are satisfied that the killers belong to a gang with bases north and south.
The main focus is on a gang with at least 15 members, who are mainly from the Dundalk area but have been living in south Armagh. Most of them are known to gardai and have been arrested previously in connection with a spate of crime in the area.
However, other lines of inquiry are also being pursued, including the possible involvement of dissident terrorists and gardai are emphatic there are several strands to their investigation at the moment.
Justice Minister Alan Shatter issued a fresh appeal to those who had information to come forward. He said: "There are husbands, wives, sons, daughters, friends and neighbours who must know the individuals involved in this crime."