AS Michael Brady wrapped his fingers around his wife Julie's neck; he was signing his own death warrant. He just did not know it at the time. In a drunken haze, he beat her, raped her and strangled her before leaving her lifeless body in the living room of the family home and heading upstairs to sleep.

Michael Brady and Julie had moved into the local authority house in Harelawn Estate in Ronanstown, West Dublin, four years earlier. To the outside world, there was no hint whatsoever of what was to come.

Brady, a keen soccer player who worked as a builder's labourer, was, as is so often the case, described as "a quiet man, [and] a great worker" by neighbours and colleagues.

As they were quizzed by newspaper reporters, they found it easier to convince themselves that there was a strangler on the loose in the densely residential area west of Dublin city that they called home.

One neighbour described hearing of Julie's death: "It's hard to believe, it's absolutely shocking. I'd be afraid to open the door. I'd met her just the day before, and she was saying she was getting ready for Christmas, with toys for the kids. When I heard she was dead I thought maybe she'd gone into a coma and died because she was a diabetic."

But Michael Brady was not the perfect husband and, to his wife Julie, he had become anything but a "quiet man". He was in fact a violent man, who would force her into sex and had beaten her on at least two previous occasions.

On Saturday, 21 December 1985, Julie Brady – née Hyland – was found dead by her four-year-old daughter Elaine. Michael Brady was upstairs asleep as his little girl found her mother lying motionless downstairs at around 9.30am.

It was unusual for Julie Brady not to be up and about making breakfast, doing the things that mothers do and as Elaine went downstairs, she saw her mum lying prone on the floor. She tried to rouse her, but Julie Brady wouldn't move. The four-year-old girl went to her father, who was asleep in the bedroom upstairs, and woke him. He was bleary-eyed but managed to feign surprise and told his daughter that everything was fine.

He went downstairs, found his wife as he had left her, pretended to try to wake her, and called an ambulance. As medical personnel arrived at the scene, gardaí were not far behind. Julie Brady was already dead and detectives immediately classified the case as "highly suspicious". The state pathologist Dr John Harbison was called to the scene to carry out the post-mortem; his results saw the investigation quickly upgraded to a murder hunt. The young mother had died of manual strangulation, and she was only partially clothed – dressed in a man's jumper – when examined at the scene.

As officers began to carry out door-to-door inquiries, it quickly became apparent that their perpetrator was very, very close to home.

Gardaí – as is their wont – were remaining coy the following day as the "hunt" for the strangler continued. There were no new leads, they said, as behind the scenes the net began to close on Michael Brady.

On Christmas Eve, Julie Brady was buried at Glasnevin Cemetery as her family struggled to comprehend what had befallen them.

Amongst the mourners that day was her brother Martin "Marlo" Hyland, a then 18-year-old wannabe criminal, who would grow up to become one of the country's most notorious drug traffickers and armed robbers.

Revenge might have been on his mind that day but of who had killed his sister, there were only the strong suspicions of his family.

Months passed and the investigation faded quietly into the background, at least as far as the general public was concerned. It was May before a decision was made to charge him with Julie's manslaughter.

For more than a year, he protested his innocence, claiming he had nothing to do with what had happened to his wife. But as the trial closed in, remorse set in and he decided he would take his punishment.

On 3 July 1987, the case finally came to court, where Brady pleaded guilty to manslaughter.

The court heard how the "Gentle Giant" – so nicknamed because of his six-foot-plus height and renowned strength – had returned home from a day's drinking and strangled his wife.

Sending him to prison for 10 years, Justice Frank Roe said that Julie Brady would have been "in agony" in the last few minutes of her life.

As he handed down the sentence, the family of the dead woman applauded.

The prosecuting barrister Martin Kennedy said that the young couple had been very much in love and doted on their two daughters, Elaine and Karen.

Michael Brady had worked for a building company but they had finished up at noon that day, because work was ending to allow employees to enjoy the festive period.

A party for the employees was organised and free drink and free food were handed out to the group who met at the Belgard Inn in Tallaght.

Even before the party had started, before they had even left work, Michael Brady had shared a bottle of whiskey with his work colleagues. He couldn't handle spirits, however.

He stayed at the party until about 11.00pm, according to work colleagues. Nobody knew exactly how much alcohol he had consumed but based on what other people were drinking, his friends reckoned it was somewhere between eight and 14 pints of Harp.

He was certainly drunk, said his workmates, and one of them gave him a lift home as he was in no state to drive.

From there, the circumstances of what followed remained unclear as Michael Brady gave gardaí a series of different accounts of what had happened. It seemed as if Julie had been polishing furniture when he got home.

Michael Brady had been violent before; on his wife's twenty-first birthday, as she carried their first child Elaine, he had viciously attacked her. It happened again and Julie Brady moved back into her parents' home in Cabra for four months, vowing she would not return unless he curbed his drinking. He agreed that he would try harder and she – like so many other victims of domestic violence – agreed reluctantly to return to the family home.

A few months before she died, Julie Brady had a strange conversation with her mother. She told her that she planned to grow her nails so that if anybody laid a hand on her, she could fight back and leave a mark on them. Her mother would then be able to determine who was responsible.

From the day Julie died, her mother Nellie never doubted who was responsible. She openly accused Michael Brady of killing her. At the mortuary where the body was held, a row had broken out between the two families, to which gardaí had to be called.

The conversation about her nails proved prophetic and it was exactly this evidence that made the definitive link between Michael Brady and his wife's death.

Under her nails, forensic specialists found his blood, while his face and neck had been severely marked in the aftermath of the attack.

When questioned by gardaí, he said that a concrete block had fallen on him at work – the explanation seemed implausible, but there was also something disconcerting about the case.

Gardaí recalled how Michael Brady gave at least a half-dozen conflicting reports of what had happened. It was confusing, they said, because it wasn't as if he was lying, rather that he hardly knew himself what had happened. The memories of what had happened appeared to have become a dream and Brady could hardly understand his part in those events.

State pathologist Dr John Harbison told the court that Julie Brady had indeed died of manual strangulation but that she had also been severely beaten around the eyes and face.

When found in the house, Julie Brady was wearing only her husband's jumper. She was face down on a blood-spattered cushion and her clothes had been ripped violently and lay strewn around her. There was blood on her own jumper, which had been stripped off her body. Since it was blood-stained, it meant that some of the blows inflicted on her must have come before she was even undressed.

As part of Michael Brady's defence, consultant psychiatrist Dr James Behan said the killer had "subconsciously suppressed" any trauma in his life, including the death of his wife. He had been abandoned by his mother as a child and when he finally got in contact with her, she spent just five minutes in his company before leaving again.

As Michael Brady was led away to serve his sentence, justice certainly appeared to have been done.

For Julie Brady's younger brother Marlo, however, the justice of a court was never going to be enough. The beginnings of a scheme were already forming in his mind.

Michael Brady went to jail and quietly went about serving his sentence. He was the very definition of a model prisoner, according to officers, and in February of 1994, he was released from jail. He was subject to strict conditions and prohibited from making contact with his daughters, visiting their home or visiting their school.

While Michael Brady had been languishing in prison, young Marlo Hyland was forging his way into a life of crime. He was not yet exactly among the top division of Irish gangland criminals but he was quickly garnering for himself a reputation for violence and the settling of scores with a bullet. By the time Marlo tracked down his nemesis, he was already suspected of involvement in two gangland murders.

Michael Brady must have had concerns and he did his level best to live a life under the radar.

At around 9.15pm on Thursday, 5 September 1996, Michael Brady's past finally found him again.

Marlo Hyland already knew that he had been released from prison and had after months of searching tracked down an exact address for him. Brady was living in an apartment complex near Ellis Street, just off the quays, in Dublin's city centre. Driving his car home that evening, he pulled up outside a car park. He was last seen putting his hand to his pocket for a swipe card to open the electronic gates that would allow him access.

A motorcycle turned in from Ellis Quay and pulled up beside his car. The window of the car was open and the pillion passenger dismounted the motorcycle and walked towards it. He pulled out a weapon and fired four shots at close range through the gap in the window.

Michael Brady was hit in the neck and upper body and fatally wounded, his seat belt still strapped around him. Death would have been instantaneous.

Descriptions of the gunman and getaway driver were vague but most gardaí are certain Marlo Hyland himself was there that day. That, however, like most other gangland secrets, was taken to the grave and the case remains unsolved.

As Elaine Hyland grew up, she was robbed first of her mother and then her father.

On Tuesday, 12 December 2006, Elaine – by then 26 – was returning to her home in Scribblestown Park in Finglas after taking her own daughter to school. As she came to her front door, dark memories of the day she found her mother 21 years earlier must have come flooding back.

Her uncle Marlo Hyland had been shot, the victim of an internecine criminal feud, while a young plumber, Anthony Campbell, an innocent at work at the house, was also dead. Marlo, by now aged 39, had been shot six times in the head after a gunman burst into an upstairs bedroom of the house.

Marlo Hyland had been in fear of his life, moving from house to house, hoping to keep clear of the many rivals who plotted to kill him, who suspected that he had become a garda informer.

Twenty-one years after his sister Julie died, he too lay dead, shot by the very men he paid to protect him, the circle of vengeance finally squared after more than two decades.

Book details - Extracted from 'Revenge' by Ken Foxe, Public Affairs Correspondent with the Sunday Tribune, the true stories of 20 of Ireland's most brutal killings and how they were explained by a simple motive – vengeance. Available in bookshops now and online at www.poolbeg.com. Published by Poolbeg Press