A child's car seat and a hammer could lead detectives to the cold-blooded killers of one of their colleagues, they believe.
Father-of-two Detective Garda Adrian Donohoe was shot in the head four weeks ago as he confronted a gang holding up a small credit union near his home in Lordship, on the rural Cooley Peninsula in Co Louth.
The raiders left behind a distinctive "precision" mallet-style hammer at the scene which it is believed was used to break the window of a car from which they stole 4,000 euro.
In a separate development, investigators have revealed a "high-end" child's car seat was in the getaway car on the night it was stolen in Clogherhead, Co Louth - about 50kms from the scene of the botched robbery.
The graphite blue automatic Volkswagen Passat, with an 08D registration, was taken on January 22, three nights before the murder. But the child seat was missing during the hold-up and detectives believe it may have been sold on to an unwitting buyer, given away or dumped and could provide a vital clue linking the five-strong gang to the crime.
Four men and one woman, all from south Armagh, are the chief suspects. It is believed one person fired the fatal shot.
The stolen getaway car was found burnt out on the edge of a forest on Cumsons Road, a back road off the main A29 from Newtownhamilton to Keady in south Armagh about an hour after the murder on January 25. Gardai believe it may have been stored in a lock-up garage or left on a street or housing estate between the time it was stolen and found.
The child's seat is described as a distinctive Cosatto brand high-back booster chair with luminous green trim, which was almost new. The hammer used in the incident has been sent to the Garda forensic science laboratory for extensive tests. Detectives said the tool is a type often used by panel beaters or mechanics who repair motorcycles and quads.
Meanwhile, chief investigator Assistant Commissioner Kieran Kenny denied there has been any downgrade of the murder investigation after reports that resources were being scaled back.
He said: "I can tell you that there has been no reduction in the resources that are there. But I will say that resources in, for instance, searches of certain areas that have been completed, or facets that have been completed, have been moved to other areas. But the same dedicated team are working on this investigation and that will remain the way."