David Mahon trial centred on the circumstances of injury

Every day of his trial, David Mahon (45) was accompanied to the Central Criminal Court by his wife Audrey, the mother of the 23-year old man he was accused of murdering.

Dean Fitzpatrick bled to death from a single stab wound to his abdomen on May 26th, 2013 following a late-night row over a bicycle water bottle. The murder trial centred on the circumstances in which he sustained the injury.

Mahon was on Friday found not guilty of murder but guilty of the manslaughter of Dean Fitzpatrick.

Mahon moved from Dublin to the Costa del Sol in Spain with Audrey Fitzpatrick in 2004 along with her two children from a previous relationship - Dean, then aged 13, and Amy, who was 11 at the time. Mahon and Ms Fitzpatrick have got married since Dean's death.

In 2008, the family was caught up in tragedy which made international headlines. Amy, now aged 15, disappeared in Spain at about 10pm on New Year’s Day, 2008 while walking home from a friend’s house via a shortcut along an unlit dirt track. Despite extensive searches by the Spanish authorities, with help from their Irish counterparts, she has never been found.

Mahon worked as an estate agent on the Costa del Sol. He told gardaí they had been millionaires, with eight or nine houses and bars, but had spent all their money looking for Amy.

In 2009, at the age of 18, Dean returned to Ireland. He met his partner Sarah O'Rourke in 2010 and they had a son together who was aged two at the time of his death. They lived in Lusk in north Co Dublin.

Mahon and Ms Fitzpatrick eventually also moved home from Spain and lived in an apartment with their cats at Northern Cross on Malahide Road in Dublin.

Mahon and Dean Fitzpatrick did not get along but nevertheless joined Northwood Gym in Santry together. The trial heard Dean had psychological issues and started misusing drugs when just 11. A few days before he died, Ms O’Rourke asked him to move out of their home because he was selling tablets. A quarter of an hour before the row in which he died, she sent him a text saying she was with someone else “to hurt him”.

Dean attended his gym the day before the fatal argument with Mahon. He saw Mahon’s bicycle outside and took the plastic water bottle off it to annoy the older man. Mahon immediately suspected Dean and pleaded with gym staff to bar him, describing him as “a known bike thief”. They said he would have to report it to the gardaí .

Instead, he spent much of the next day drinking and trying to get in touch with Dean. He eventually convinced Dean to come to his apartment that night.

CCTV showed Dean entering the building at 11.06pm and Mahon leaving seven minutes later. In the short time Dean was inside, the two men had rowed and the knife Mahon was holding had fatally wounded Dean.

There were two witnesses present: Mahon’s friends, Karl O’Toole and John McCormack.

Mr O’Toole said in evidence he thought the row had been resolved when Dean left and Mahon followed him out of the apartment. Mr McCormack left with Dean, but he did not give evidence, which the jury was told not to speculate about.

Mr O’Toole said he was working as a taxi driver when he got a call from Mahon around 10pm.

“I said I could be down in a couple of minutes,” he recalled. “He was drunk… He was agitated… He needed help or someone to talk to.”

Mr O’Toole said Mahon was trying to get Dean to come to the flat. He eventually arrived and Mahon put it to him that he had “robbed” a piece of Mahon’s bicycle. Dean denied it until Mahon told him that it had been caught on CCTV, he said.

“Dean admitted he did take the part but just did it to annoy him,” he said, adding that both men were agitated. “Dean said he’d return the part the following day. He got up then and left.”

He said Mahon told him he would be back in a minute and also left. He was gone 30 seconds to a minute.

“Everything sort of went from zero to a hundred in a short space of time,” he said. “When he came back in, he was holding a knife.”

Prosecution counsel Remy Farrell told the trial: “It’s what happened when he walked out the door that’s the issue. David Mahon arrived back in and had a carving knife. The prosecution case is that David Mahon stabbed Dean Fitzpatrick in the abdomen.”

Mr O’Toole told the court that at Mahon’s request, they left the apartment and drove around for hours. “David wasn’t really making any sense. I was trying to find out what happened.”

Mahon asked him to stay off the motorways because of CCTV and they used back roads. He eventually brought him to Mahon’s father’s house.

“I think David said to his father that Dean came at him with a knife but Dean ended up being stabbed,” he said.

The jury heard Dean ran off, collapsed nearby and was tended to by strangers. He died the following day.

Mahon was shaking and crying when he went to gardaí the morning after the incident, accompanied by Mr McCormack.

He told gardaí Dean had produced a knife, and he had taken it off him, putting it in his back pocket. He said his friend, John McCormack, had taken Dean out of the apartment and he followed them.

“I took out the knife and said: ‘What are you doing, pulling a knife on your father?’ And he walked into the knife. He was putting it up to me and he walked into the knife.”

He said it was a knife from his kitchen block and Dean had previously pulled a knife on him from the same block.

Mahon said he had thrown the knife out of the window of the car when he was being driven around by Mr O’Toole after the incident.

Defence counsel Sean Guerin said in his closing speech at the trial that Mahon’s account was of a tragic accident, which occurred without any deliberate act or intention on his part to kill or cause serious injury. He said none of the scientific evidence contradicted it.

“He had no motive to kill and every reason in his relationship with and love for Audrey Fitzpatrick not to harm Dean Fitzpatrick,” he said.