Garda Horkan’s death on duty was a stark reminder of the dangers faced by gardaí every day and the real threats they encounter in fulfilling their duties. It was one of those events — such as the killing of Adrian Donohoe, a Garda College contemporary of Horkan’s, in 2013 — which brings Irish society up against that reality.

There were emotional scenes at the conclusion of the trial as Gda Horkan’s family acknowledged the stress of the proceedings and the loss they had endured.

In tributes paid by friends and colleagues, we learned that Mr Horkan had had a huge interest in sport — he played Gaelic football at underage level with his native Mayo and was a lifelong Liverpool fan, cherishing a photograph taken with Ian Rush of that club.

On learning of Horkan’s death, Rush sent a message of condolence to the family. I want to let them know, he said, that they will never walk alone.

Ar dheis Dé go raibh sé.