JUSTICE Minister Alan Shatter says the gang that murdered Detective Garda Adrian Donohoe must have known gardai would be escorting the credit union cash.
They were "intent on murder and mayhem".
The Irish Independent reported yesterday that gardai are satisfied their colleague was lured into a trap and deliberately ambushed.
Mr Shatter said he was confident the gang would be apprehended. The murder, at Lordship, outside Dundalk, was "an attack on all members of the force" and on the State.
"Everything that is necessary to bring these people to justice will be done."
The minister said that if the gardai had not been there, a member of the credit union staff could have been killed.
"Quite clearly the gang that was engaged in this event, on the assumption there was some pre-planning, must have known there was some garda security for cash coming from the credit unions.
"They were quite clearly armed. They gave Garda Donohoe no chance of any description. This man had no chance to say anything and even to reach for his own weapons. He simply was shot in circumstances where there was no hope of survival," Mr Shatter said.
"It's quite clear this was a group of people intent on murder and mayhem, they had no respect for human life. It may well be the case that if the gardai had not been there, a member of the credit union could have lost their lives.
"So quite clearly these people had no compassion, no moral compass of any description and it is of the utmost importance that they be tracked down. The Commissioner and all those working on this investigation are dedicated to achieving that outcome," he stressed.
Mr Shatter was not ruling out the involvement of dissident republican elements in the robbery and murder.
"I don't want to prejudice whether this is an act by a group of criminal terrorists flying the Tricolour for convenience or whether this is a group of organised, or perhaps disorganised, criminals hellbent on financial gain who show no respect for human life," he said.
The minister travelled to Dundalk to meet members of the gardai following the murder. He will also meet the Donohoe family at a later date.
Mr Shatter discussed the situation with his Northern Ireland counterpart David Forde at the weekend. He emphasised that gardai had the resources to catch the killers and reiterated that he didn't feel additional legislation was required.