The man who killed Det Garda Colm Horkan fired 15 shots from the garda's weapon, hitting the victim four times.
Garda scene-of-crime examiners spent much of Thursday extracting spent rounds from surrounding walls and buildings on Castlerea’s Main Street, following the shooting which occurred just before midnight on Wednesday in the Roscommon market town.
Sources said the man fired the handgun wildly after seizing it from the 49-year-old detective.
The suspect, a local man in his 40s, was tackled and arrested at the scene by two gardaí from Castlerea station, who were passing the scene in a patrol car.
“The only reason they weren’t hit too was because he had used all the ammunition by then,” a Garda source said.
Garda Commissioner Drew Harris said the shooting served "no purpose" and was an "aberration" in Irish policing. There was "no sign of a bigger picture, either organised crime or subversives", he said.
Suspect’s behaviour
The suspect, who remains in custody, has a history of mental health issues and drug and alcohol abuse. He had been brought to Castlerea Garda station for a period the previous day due to his behaviour, it is understood.
Det Garda Horkan was on an anti-crime patrol in the town on his own on Wednesday night when he encountered the suspect operating a motorcycle and acting erratically, sources said.
It is understood the garda got out of his car and engaged the man in conversation before a struggle broke out. It is believed the garda did not draw his weapon and that the man may have wrestled it from its holster before firing it. The weapon holds 15 rounds, all of which were fired in short succession.
Det Garda Horkan, who lived in Charlestown, Co Mayo, had been appointed to plain-clothes duty a few weeks previously, having spent most of his 24-year career in uniform.
He is the 89th garda to be killed in the line of duty since the foundation of An Garda Síochána almost 100 years ago.
He attended the Garda Training College in Templemore in 1994 at the same time as Det Garda Adrian Donohue, who in 2013 was shot dead during a credit union robbery.
Last Rites
Gardaí and emergency workers who attended the incident on Wednesday night tried to save Det Garda Horkan’s life but he died at the scene. Castlerea parish priest Fr John McManus arrived and administered the Last Rites as emergency workers said a prayer.
A postmortem on the remains was carried out on Thursday evening by the State Pathologist. The Garda has launched a full murder inquiry while the Garda Ombudsman has also opened an investigation, in line with standard procedure when a Garda firearm results in death.
Mr Harris said while all aspects of the Garda's resources, tactics and policing methodology would be reviewed in light of the fatal shooting, there appeared to be unique characteristics to the crime that may not necessitate major changes in the Republic's policing.
“We’d have to think very carefully before we would change our policing tactics. Our policing tactics are successful in that we enjoy the full support of this society,” he said.
Det Garda Horkan is survived by his father and five siblings. President Michael D Higgins said his death was "a shock to us all".
"As President of Ireland I wish to express my deepest sympathy to the family and friends of the garda, and to all those who have been affected by this tragedy," Mr Higgins said.
