This is Grangewood, a peaceful middle-class development in Strabane, Co Tyrone.

The children laugh and twirl a pink umbrella, pretending to be princesses.

You'd never guess that nearby sits double killer John Gallagher.

Just 12 miles across the border in St Patrick's cemetery, Killygordon, Co Donegal, lie his victims, Anne and Annie . . . known to her friends and family as Dodie . . . Gillespie. It's almost 18 years since John Gallagher blasted his girlfriend and her mother to death in the grounds of Sligo General Hospital. He has never spent a day in jail for it.

The Sunday Tribune parks near the house where Gallagher, his wife Caroline, and their children now live. But Gallagher spots us and jumps into a car. He pulls down the sun visor to hide his face. He looks unremarkable . . . a balding, middle-aged man with a thickening waistline. He stops at the bottom of the street, watching us walk towards his house. Then, he drives off.

A dark-haired boy, in his early teens asks: "What do you want?"

"Is your father in?"

"No."

"Is this the Gallaghers?"

"No."

A small, blonde woman in her mid-30s stands in the hallway of the neat semi-d.

The front door closes. The Sunday Tribune rings the bell twice. No one answers. The blinds are then drawn.

Minutes later, the Sunday Tribune is phoned by police investigating "suspicious activity" outside a house in Strabane. The occupants have reported our registration number. We explain our actions.

The police are shocked.

They've no knowledge of a killer at that address. The woman who made the complaint hadn't used the name Gallagher. The officer speaks to her again. When told why we visited the house, he said she replied, "That's the past and this is the present." Not everyone can forget so easily.

Phonsie Lafferty is a man of few words but what he says comes from the heart: "John Gallagher shot my sister and my niece and it had no more effect on him than if he'd shot rats. It wasn't spur-of-themoment, it was carefully planned and executed. Somebody like that could kill again."

Anne Gillespie was just 15 when she started dating Gallagher, a 19-year-old van driver from Lifford. "I never liked him, " says Phonsie. "He always had to be top dog. But I kept my thoughts to myself and accepted him for Anne's sake."

Phonsie looked out for his sister Dodie (56) and her only child. Dodie's first husband died young. Then, she married Anne's father. He died when Anne was threemonths old. "Dodie wasn't one to complain but she'd a hard life, " says Phonsie.

Mother and daughter were close. They were a familiar sight, walking the Co Donegal roads together. There was no money for a car. The women lived in a small, two-bedroom house on the outskirts of Ballybofey. Dodie was a parttime cleaner. Anne worked in a local shop during school holidays.

"Dodie kept herself to herself, just as I do, " said Phonsie. "Anne was far more outgoing. She had done her Leaving Cert and was starting a secretarial course at college. She had lots of friends. She liked make-up and dresses. She thought she was very grown up, and she was in some ways, but in other ways she was just a child."

It's no wonder John Gallagher was crazy about her.

She was a striking young woman with dark eyes, long curly red hair, and a great figure. There's a video of John and Anne at a wedding eight days before he killed her.

Anne looks stunning in a green dress, but she doesn't seem happy, even when holding hands with Gallagher. She smiles only once . . . when she is dancing with a young neighbour and Gallagher is out of sight.

She paid a high price for that dance. Gallagher later threatened her dancing partner. Then, he went to Anne's house and slashed himself with a knife. He smeared Anne and himself with his own blood.

Five days before she died, Anne celebrated her 18th birthday. Friends say it was a turning-point. She was sick of Gallagher's possessiveness.

She told him she wanted to end their three-year relationship. He wouldn't accept it. He wanted to marry her and build a house for them to live in her mother's garden.

Two days later, he raped her. Then he dragged her from her home and tried to bundle her into his car. But a worker in the tyre depot across the road stopped him.

"Gallagher stood in Dodie's kitchen, took a knife out of the drawer, and said there'd be blood spilt soon and it wouldn't be his. He told us he'd hurt his head in an accident as a child and he'd plead insanity in any court case, " Phonsie says. "He was very calculating."

Anne reported the rape to gardai. "Gallagher went and signed himself into St Conal's psychiatric hospital and Anne started to feel sorry for him, " says her uncle. "She didn't want to ruin his life. She was too soft. It was her downfall."

Anne withdrew her complaint. Gallagher immediately signed himself out of hospital. Anne and Dodie were now terrified. Gallagher had keys to their home. Phonsie changed the locks. The night before they were killed, he called to the house.

"They'd bolted all the doors, virtually barricading themselves in, " he says.

On the evening of 18 September, the family went to Sligo hospital to visit Anne's granny who had a broken hip.

There was Anne, Dodie, Dodie's sister Della, her husband Patrick McGuire . . . who was driving . . . and their three children, packed into the car.

Dodie's other sister Teresa, who has spina bifida, was also there.

They were unaware Gallagher had followed them. As they were leaving the hospital, he rammed their car. One of the children started screaming, "It's John Gallagher and he's got a gun, " and ran from the car. Her mother and two brothers ran after her, although the boys shouted, "It's okay mammy, it's only a pellet gun!" Patrick, Teresa, Anne and Dodie were trapped in the car.

First, Gallagher tried to shoot Patrick but the .22 rifle jammed twice. He reloaded the gun and walked to the back of the car.

"All I want is you, " he said to Anne, before shooting her three times in the neck and once in the thigh. Then, he blasted Dodie in the face, ranting that she was "an oul bitch". Teresa was drenched in her sister's and niece's blood.

Gallagher drove off. At his trial, he had a first-class legal team. "We didn't stand a chance, " says Phonsie. By a 10 to two majority, the jury found him guilty but insane, which technically didn't amount to a criminal conviction. "We felt as if the lives of Anne and Dodie didn't matter."

Gallagher was sent to the Central Mental Hospital in Dundrum. Within months, he began applying for his freedom, claiming he wasn't insane at all. "We sold Dodie's house and used the money to try and fight him in the courts, " says Phonsie. "We wanted him in prison, not hospital, but hospital was better than nothing."

Gallagher enjoyed remarkable liberties. He was allowed to work in a glass factory where he earned 450 a week. He drove a motorbike and was let out for weekend breaks. One Saturday, six years ago, he didn't come back.

He was later found by English police in a Tesco car-park in Oxford, trying to sell his story to the News of the World.

Phonsie and his family wanted Gallagher extradited to Ireland. But there were no grounds to do so as technically he had no criminal conviction. A police psychiatrist interviewed him, deemed him sane, and he was released.

Gallagher then married Caroline Southern, from Rathdrum, Co Wicklow, whom he had reportedly met on weekend breaks from the Central Mental Hospital. He got a job as a store manager in Birmingham and settled in a mock Tudor house in a nice part of town. But he missed his family in Lifford.

Three years ago, he moved to Strabane.

Then, sources say, a Real IRA death threat forced him out. But he has now returned and seems comfortably settled. As Strabane is officially in the UK, he can come and go as he pleases. If Gallagher sets foot in the Republic, he could be arrested and returned to the Central Mental Hospital. But Phonsie thinks he visits Lifford anyway. "Why wouldn't he? It's not as if the guards are waiting at the border for him."

Other relatives, like Patrick and Della McGuire, believe Gallagher is still dangerous and are concerned for their own safety. Phonsie remains angry: "Every step of the way, John Gallagher has managed to beat the system. The state basically washed its hands of the case.

"The first seven years after the shooting were tough. Had the opportunity arisen, I'd have killed him for what he did. Now, I wouldn't. It would destroy my family and he's not worth it. He's the lowest form of life."

Phonsie's eyes fill with tears and he won't speak further about Anne and Dodie.

"There are things I want to keep in here, " he says, touching his heart. "My only comfort is, had Anne lived, she might have given in and married John Gallagher. What sort of life would it have been?

At least she was spared that."