'It's only a matter of time before we get you and you're dead," the recorded telephone message crackles ominously, but the words are clear. The man on the phone continues to threaten Ian Kenny, who lost his fight for life nine days ago after being shot by his friend two years ago.

"Rat," mocks the caller. "We'll run through your house if we want." Kenny, who had become accustomed to these phone calls, responds nonchalantly, addresses the abusive caller by name, and tells him he isn't afraid. A few months after that call, the 21-year-old was shot in the head.

The father-of-two from Crumlin was shot by one of his closest friends, Jonathan Dunne, on 4 July 2007 in Stillorgan, south Dublin. It is one of the most unprofessionally planned attempted murders gardaí have ever investigated. On the day of the murder, Dunne took Kenny on a drive with another friend of theirs. He parked at Stillorgan shopping centre, went to the boot and took out a sawn-off shotgun. He walked to the window of his own car and fired two shots at point-blank range into his friend.

Kenny was then thrown from the car and the pair drove to a nearby wooded area where they unsuccessfully attempted to burn the car. Dunne then panicked and began running up the Lakelands Road where he was noticed by a passing patrol car. He was covered in Ian Kenny's blood and brain matter. Much to the unhappiness of the Kenny family, charges against the other man were dropped but Dunne (24) was jailed for 12 years for the attempted murder.

In court, he said he shot his friend as a favour to a drug-dealer who he owed £50,000 after he lost a consignment of drugs seven years earlier. "Jonathan Dunne told a story to the judge and the judge believed it. Dunne killed my son; why did the court believe the story of a killer?" asks his father, Jon Kenny. "I know who was responsible for my son's murder and he wasn't killed because Dunne owed a drug dealer money. I don't care what the gardaí have been saying, I can tell you without any doubt in my mind that Freddie Thompson was not behind my son's killing."

In court, Dunne described the incident as "the most horrible moment of my life... If I could take it back I would." But in Mountjoy prison, where Kenny's elder brother Jonathan is also incarcerated, his remorse has completely disappeared.

"When he sees my other son, he makes jokes about what he did. 'Is it vegetable soup we're having today?' he shouts, in reference to Ian's condition before he finally passed away. He also tells Jonathan that our family should expect his car valeting bill because of all of my son's blood that was spilt in his car," continues his father, anger in his voice. "Are those the words of a remorseful man?"

In 2004, a dispute between the Kenny family and a well-known local crime family in Crumlin erupted, and this ultimately led to Ian's killing, according to his father. It began over an allegation that Jonathan Kenny was a "rat", or garda informer.

His family believe the rumour was started by gardaí – a claim strongly rejected by garda sources. Like most criminal feuds, it quickly spiralled out of control. Jonathan and Ian Kenny were stabbed but survived in 2004 and two years later, the family home on Monasterboice Road in Crumlin was targeted by a gunman. Sergeant Mark Clarke was struck by 11 pellets in the chest and arm as he stood outside the house and was lucky to survive.

Clarke had been on duty protecting the Kennys after shots had been fired at their home. While Clarke lay injured on the ground, Ian Kenny went up to the injured officer and said: "Die, you bastard, die."

Ian Kenny was not an angel and knew he was going to die and used to joke about it. "My son was not in a gang. This was not a gangland murder. I used to ask him, 'Son, why are you having a few drinks?' He'd say, 'I'm trying to enjoy myself before I get shot.' I told him not to trust anyone who was a drug pusher. But he trusted Jonathan Dunne and that man was in this house playing with Ian's kids."

Dunne was related to the family the Kennys were feuding with but the ties did not appear to be strong. Ian's father believes his son was shot on the orders of Dunne's criminal relatives ? the same men who frequently threatened to kill him and other members of the family ? not Freddie Thompson. One of the members of this well-known Crumlin crime family was working as a driver for Thompson at the time.

Garda sources believe Thompson arranged the shooting. But the Kennys are adamant the family with which they were feuding ordered the murder of their own volition.

"I know Crumlin and everyone in it. It was not Thompson who gave the order," said his father.

The family knows that, ultimately, it doesn't matter who ordered his killing, what matters that is that Ian is never coming back.

After his death last Friday, his partner Linda's mother placed a cross and chain around his neck, but the cross fell to the ground. "She said, 'The heavy cross that he's been carrying around has been lifted off him.'

"Truer words about my son have never been spoken."