THE young man who stabbed Sebastian Creane in a murder-suicide last year had taken a potentially fatal dose of anti-depressants.
Toxicology results have confirmed the suspicions of Shane Clancy's family by showing high levels of prescribed drugs in his system -- but no alcohol.
Mr Clancy from Dalkey, south Dublin, attacked Sebastian Creane (22), his brother Dylan (28) and his ex-girlfriend Jennifer Hannigan (22) at a house in Bray last August, before taking his own life.
Sebastian suffered fatal stab wounds, while Dylan and Jennifer were seriously injured but have since recovered.
Tests have now suggested that Mr Clancy had taken an overdose of anti-depressants before the tragic attack.
The Trinity student is believed to have started taking medication to counteract depression just weeks before the stabbings on August 16.
He had told friends that he did not like the way the drugs made him feel but continued to take them. In the aftermath of the tragedy, his mother Leonie Farrell revealed her own fear that tablets had affected his thinking.
After attacking the three young people, he turned the blade on himself, inflicting more than 20 wounds and eventually hitting the main artery to the heart.
He lay dead in the back garden of the Creane house for several hours before being discovered by gardai.
The tragedy shocked the country and raised serious questions about the sale of knives.
Jennifer Hannigan had previously been in a relationship with Clancy but after it ended she began dating Sebestian Creane.
On the night of the stabbings, Clancy spent some time in the company of Creane and other friends in a pub before offering him a lift home.
After discovering where the Creane house was, he drove a few miles to Dunnes Stores in Cornelscourt where he purchased a block of knives.
Gardai have pieced together most of what happened but the exact sequence of events inside the house may never be clear.
It is thought that he gained access by knocking on the front door and then attacked Sebastian with a knife.
The noise alerted Dylan and Jennifer who were then targeted but not fatally wounded.
Clancy's mother Leonie has described how she had taken Shane to a doctor because of his depression. He was given a month's supply of anti-depressants.
"All I know is that Shane wouldn't hurt a fly but turned unrecognisable that night for some reason," she said.
The signs of his depression emerged at the start of the summer. She said she insisted he seek medical help because she couldn't bear to see his heartache.
"I drove him to the doctor and made him get some anti-depressants which he didn't want to take but I insisted," she said.
An inquest into Clancy's death will take place on April 15.