Garda Commissioner Martin Callinan has warned the killers of detective Adrian Donohoe to “keep looking over your shoulder”.
On the eve of the first anniversary of the Dundalk officer’s death, the Garda chief said the force was keeping a close eye on the suspected murderers.
“I say to the people involved in this particular crime - keep looking over your shoulder,” he said.
Father of two Garda Donohoe was gunned down during a botched Credit Union robbery near his home in Lordship, outside Dundalk, on January 25 last year.
The detective was escorting a cash delivery when he stepped out of his patrol car and was shot in the head by one of a four-man criminal gang, believed to be based along the Irish border. The killers fled with just 4,000 euro and dumped their getaway car in Keady, Co, Armagh.
Mr Callinan, the Republic’s most senior police officer, said the force is satisfied they know the identities of the murderers. “Suffice to say we are keeping a very good idea on the target,” he added.
The mammoth investigation has seen officers travel to Belfast, the Netherlands and the United States.
“We have sent officers to a number of these countries to try gathering intelligence and indeed evidence,” said Mr Callinan.
He praised the “invaluable” help given to the murder investigation team by the PSNI, the FBI and Europol.