Garda Commissioner Martin Callinan said the entire force had been deeply shocked and saddened by the murder of Detective Garda Adrian Donohoe - the first of a serving officer in 17 years.
Commissioner Callinan said: "He was a very popular member of An Garda Siochana, a very efficient member, someone who was revered both by his peers and members of the community where he served."
A wide police cordon extending for several miles was still in place around the crime scene outside Lordship Credit Union at Bellurgan, Jenkinstown which is about seven miles outside Dundalk.
Specialist officers from the Garda Forensic and Technical Bureau were combing the area for clues and could be seen scouring the bushes and hedgerows lining the rural roads. A blue tent was erected in the Credit Union carpark where the officer was tragically cut down.
The slain officer's body was taken away last night to Our Lady of Lourdes Hospital in Dundalk where a post mortem examination was expected to be carried out.
Taoiseach Enda Kenny has said the murder of Detective Garda Adrian Donohoe, who was shot dead in Ireland last night in a botched hold-up was an "outrageous and appalling act of cold blooded violence". He said:
Garda Commissioner Martin Callinan said he had been deeply saddened to hear of his colleague's death.
A detective gunned down during a botched bank heist in Ireland was killed less than half a mile from his home.
Detective garda Adrian Donohoe, a father of three in his 40s, died as he tried to prevent raiders escaping with cash from Lordship Credit Union at Bellurgan, Jenkinstown about seven miles from the border town of Dundalk, Co Louth.
The Irish minister for justice, equality and defence, said the public will share his "revulsion and horror" over the murder of Detective Garda Donohoe.
Alan Shatter said: "I have been informed by the Garda Commissioner of the dreadful news of the brutal murder of Detective Garda Adrian Donohue who was on duty in County Louth last night.
"The Irish people rightly have great respect and admiration for members of An Garda Siochana and the work they do in protecting the community.
"They will share my revulsion and horror that a Garda has so tragically lost his life in the course of his duties.
"I know that An Garda Siochana will spare no effort in ensuring that those responsible are brought to justice."
"In doing so, they have the unswerving support of the Government and Irish people at this very difficult time."
A police officer shot dead yesterday during a botched robbery in County Louth, Ireland, was named by Gardai today as Detective Garda Adrian Donohoe.
Detective Garda Donohoe, who was attached to the Detective Unit in Dundalk, died following a shooting incident at the Lordship Credit Union at Bellurgan, near Dundalk, at around 9.30pm last night.
Garda Commissioner Martin Callinan, said:
It is understood that the Garda detective shot dead tonight in Ireland during a botched hold-up detective was married with three children.
He lived in the Lordship area near the credit union where he was killed.
Local councillor Jim Loughran knew the detective and described him as a quiet, decent family man.
"I just spoke to him last week on the street in town. I can't believe this has happened," Mr Loughran said.
The Sinn Fein councillor condemned those responsible for the shooting, saying they had devastated a small tight-knit community.
"This was not just an attack on a Garda detective, it was an attack on the whole community," he said.
A Garda detective has been shot dead tonight in Ireland during a botched hold-up.
The Garda officer in his 40s was among colleagues who were escorting a cash delivery to a credit union in Dundalk, Co Louth.
Several shots were fired during the incident at the Lordship Credit Union, on the Cooley Road in the town at around 9.30pm.
It is believed the force is now hunting four men in a grey Volkswagen Passat which fled the scene.
The officer, who was based at Dundalk Garda station, was fatally injured in the shooting.