A leading psychiatrist says Seamus Dunne is neither psychopathic nor sociopathic. Yet on a winter Saturday afternoon two years ago, he strapped an ammunition belt with 20 cartridges around his waist, walked the short distance to his neighbours' house and shot both dead with a double-barrelled shotgun.

Dunne himself seemed to be at a loss to explain it. "I flipped. I did not want any of this to happen. I was minding my own business. I have two children and a wife that I adore," he told gardai after the shooting.

The 43-year-old council worker felt "under siege" from his neighbours, the Cullys, almost as soon as he moved to the Co Westmeath village of Turin eight years ago. Twelve months after he bought the £22,000 house, he made his first call to Mullingar Garda Station.

Over the next five years he made four or five complaints to local gardai over what most people would consider minor problems. Differences of opinion over trees and bushes and a leaky septic tank on the Cullys' lands were typical examples.

But in Dunne's mind, the small things formed a pattern that added up to what he described as "abuse". One of his last calls to the gardai was in November 1996, when he rang the station to complain that the Cullys were causing a disturbance by using bangers and crackers to celebrate Hallowe'en.

There followed a period of what gardai describe as relative calm. However, although Dunne had stopped calling the gardai out, his anger was still simmering. It came close to the boil on the morning of Saturday, November 8th, 1997, when he had words with Vincent Cully over plastering work that labourers were doing on the Cullys' front wall. Dunne accused the plasterers of soiling the pillar of his wall.

That afternoon, things got worse. Dunne telephoned Mullingar Garda station at 2.09 p.m. and alleged that stones being used to pebbledash the Cullys wall were being thrown at his house. Twenty minutes later, a garda arrived at his home. He spoke to both the Dunnes and the Cullys and got two different versions of events. He left at 2.45 p.m. with the impression that he had sorted the matter out.

Less than half an hour later, Seamus Dunne emerged from his house with a shotgun. He raised the gun to his shoulder, aimed it at Vincent Cully and shot him in the right arm. He emptied the second barrel into Cully's back as he stumbled towards his house. He then reloaded the gun and shot Mary Cully in the back from a distance of over 20 feet.

Both husband and wife died within minutes in their front yard.

Dunne loaded his gun again and was raising it to shoot one of the labourers when Mrs Dunne emerged from their home and stopped him.

Dunne was "very forthcoming when arrested" and expressed "great sorrow and regret" at what happened, according to gardai. However, he told them he "couldn't allow the abuse to continue".

Locals were shocked by the killing of the popular couple. Journalists got a taste of that anger in the 24 hours following the murder. Photographers were threatened with violence for taking photos of the exterior of the Cullys' home. Outside Mass the morning after, even the gentlest queries from the media met a wall of silence.

The Cullys were known to everyone in the area because of their involvement with the local camogie club. Vincent Cully was 59 and had retired from work at the Tarkett vinyl floor covering factory in Mullingar. Mary was 54 and had looked after her mother until her death a year before the shootings.

The local GAA club had bought a silver tray for the couple as a token of thanks for their work with the camogie teams. It was to be presented to them at a function the following weekend. Instead, it served as a gift for the Offertory of the couple's Requiem Mass.

Dunne had always kept a much lower profile in Turin. While he wasn't locally considered an odd character, he was someone who kept very much to himself. A gun-licence holder since he was 16, he preferred the solitary pursuit of game to the camaraderie of the GAA club. He was the proud father of two young children. The only clue in his past of what was to come was a conviction for assault in the 1970s.

In a report to the Central Criminal Court about Dunne's mental condition, the director of the Central Mental Hospital, Dr Charles Smith, said he was neither psychopathic (mentally deranged) nor sociopathic (suffering from a personality disorder characterised by asocial or antisocial behaviour). He said Dunne's rage had distorted his perceptions and led him to respond in a manner that was totally disproportionate.

DUNNE'S explanation to gardai immediately after his arrest was similar: "When you have things like that playing on your mind for so long . . . it just broke me down." If pebbles were thrown at his house that day they had unleashed years of simmering resentment and in his rage he felt executing his neighbours was the only way to stop "the abuse".

Dunne's breakdown has taken a heavy toll on the community of Turin. The Cullys' two sons and three daughters were orphaned. Dunne's wife left her home and went to live with relatives, who have reported at least one incident of apparent intimidation to gardai. "There's still a lot of anger in some sections the community and a lot of hatred has been directed at one member of Dunne's family," a local explained.

The two Dunne children have lost their home and their father is in prison. His wife is expecting a baby, and the child will be lucky to see its father before its 10th birthday.

Turin is without two of its most valued residents and the loss still hurts. Dunne's empty house was burned down just under a year ago. The building was subsequently levelled. A criminal investigation into its destruction is still open. While the destruction of the house removes the last physical reminder of Dunne's time in the village, the pain and anger caused by the double killing will endure for many years to come.