GARDAI have established that the getaway car used by the gang who murdered Det Garda Adrian Donohoe outside a credit union premises last Friday was stolen in Clogherhead, Co Louth, earlier in the week.
The car, a dark grey VW Passat, was found abandoned in a wood near Darkley in south Armagh on Sunday.
Forensic tests on the car, which was burnt out, have allowed that gardai to identify it - and determine that it had been stolen shortly before the robbery.
The find has firmed up the theory that a cross Border crime gang, responsible for a spate of robberies and burglaries in the north Louth and south Armagh area in the past couple of years, carried out the murder.
A number of that gang are already well known to the gardai and the PSNI.
The Passat was driven erratically away from the murder scene at Lordship, Jenkinstown, on Friday night and headed directly for the Border.
Officers have appealed to anyone who spotted a speeding Passat on either side of the Border that night to contact them at the murder investigation headquarters in Dundalk, or on the garda confidential line, 1800 666111.
The Irish Independent revealed that Garda Donohoe had been deliberately targeted by the gang, who jumped over a wall to shoot him as he stepped up of his patrol car to find out why the exit from the car park was blocked by the Passat.
He was shot in the head at close range by one of the killers.