PETER Heron had been busy that intensely hot Friday in August.

There was the usual contract negotiations, office work, a last-minute dash to meet a ordinary, hurried working day. He then went home to find his beautiful wife dead, face down, her throat cut, on the living room floor - and nothing was ever ordinary again.

'I'm not the man who got away with it,' says husband of Ann Heron

“I remember the door was wide open, which was most unusual,” says Mr Heron, now 80, his voice steady. “It was a very hot day. Our dog was outside which was another very unusual thing.

“I walked inside and shouted, ‘hello Ann,’ walked into the lounge...” Mr Heron stops talking. There is a moment of silence.

Later he tells of touching Ann as she lay dead. The blood from his hands was left on the phone as he first called 999 and then his work colleague and good friend, Paul Stiller, who worked nearby.

The blood was also found on the roof of his white Mercedes where he went outside and leaned for support sobbing and waiting for his friend, and the police, to arrive. “I was in one hell of a state.”

Debbie Simpson, 53, his daughter from a previous marriage, points out that nothing was disturbed, nothing was taken and there was no forced entry. This was no burglary gone wrong.

She is quieter than her father but it quickly becomes clear that Mrs Simpson is a woman driven to prove her father’s innocence and it is in her beautiful, large, immaculate home that our interview is taking place.

Mr Heron, most keen to discuss his grievance at ever being charged with Ann’s murder, murmurs agreement with his daughter: this had been no burglary. “Ann was in a bikini, she would never ever have let anybody into the house like that.”

So what did lead to the death of Ann Heron, that sweltering hot day 25 years ago?

Ann Cockburn had met Peter Heron, a successful man from North Ormesby, Middlesbrough, when Mr Heron was on a golfing holiday on the Isle of Bute, off the west coast of Scotland in 1984.

Mr Heron had been married for 20 years to Catherine and the couple had three children, Debbie and her younger sisters, Jacqui and Beverley. Ann, originally from Glasgow, was nine years younger and had previously been married to a police officer for 15 years and also had three children.

They enjoyed each other’s company and, when Ann later came to visit a friend in Darlington, they met up and it became something more. In 1986 they married at the Methodist Chapel in Yarm Road, Darlington and had a big reception at Wynyard Hall.

The happy couple set up home at the large, white, detached 1930s house known as Aeolian House, near where the A67 road to Yarm meets the A66, and Mr Heron continued to work as operations director at GE Stiller Transport, a thriving hauliers based at the nearby village of Middleton St George. Ann worked as a part-time care assistant.

Both had found new love and were living in a beautiful home with close family, plenty of friends and with Mr Heron working as a highly respected, successful man: a dream life. Then came Friday, August 3, 1990.

As her husband got on with his busy, working day, Ann took the chance to enjoy the sunshine and relax. She had been shopping in the morning to buy a present for an 18th birthday party she was going to attend that night. She then went home where she met her husband at about 1pm.

Aeolian House was just a few minutes’ drive from Mr Heron’s work and, as was typical, he popped home for a cup of soup and a sandwich. They chatted, no big drama, no argument and Mr Heron left, saying, ‘I’ll see you later.’ It was the last time anyone saw Ann alive. Anyone, that is, apart from one person.

Mr Heron was back at the office by 2pm but after 3pm drove to nearby Cleveland Bridge for a meeting about a potential contract and left by about 4.30pm. He drove back to the office via Croft and through Middleton St George village, not the most direct route, before, his day done, going home at about 6pm.

Ann, meanwhile, went back to sunbathing. She had moved her sunbed to the front of the house to escape dust kicked up by a farmer harvesting a neighbouring field. That meant she could be seen, lying in her bikini, from tall vehicles on the nearby road. The house was not especially secluded but was separate from other properties – easy to spot and easy to attack. Just a week before a prowler had walked up the 50 yard driveway, frightening Ann into the home.

Police believe Ann was killed at about 5pm. There was no sign of any struggle and no sexual assault, although her bikini bottoms were removed. Her glass remained half full, the radio still blaring. Her half-read book, The Ghosts of Flight 401 by John G Fuller, was about 15 metres away with a pair of shoes beneath a tree. Ann’s beloved collie, Heidi, was found distressed and never again could be persuaded to trust a stranger.

But nothing was taken from the house. It was as if her body was simply dumped in the impeccably tidy lounge, face down in a pool of blood.

There was no DNA evidence found in the house belonging to a stranger although, crucially, five people, a taxi driver and a family of four, did report seeing a dark blue Ford Sierra driven by a man in his early 30s, speed out of the 50-yard driveway at Aeolian House and drive dangerously, nearly crashing into another vehicle.

These facts, the lack of struggle, the blue car, the frustrating lack of evidence, have been swirling around the heads of Mr Heron and his daughter, Debbie Simpson, every day for 25 years.

In fact Mrs Simpson, who, heading home from Whitby, had passed Aeolian house just five or ten minutes before her father returned home and, if her then-small children, Gary and Andrew, had not been sleeping would have called in. She insists that Ann must have known the killer.

It feels impertinent, sipping her coffee in her living room with her 80-year-old father sat in front of us, but it is an obvious question. Was Ann was having an affair? It would explain a man seemingly able the house with no struggle who did not burgle the house. There’s a clear ‘no’ from Mrs Simpson who nevertheless is firm in her belief that Ann must have known the man who attacked her. Her father stays silent on the issue.

But, as is well known, Mr Heron was in fact having an affair. He didn’t immediately tell police about his dalliance with a 32-year-old barmaid, fizzling out at the time of the murder, and it almost certainly turned public opinion against him at the time. However, it does explain why he chose to drive through Croft instead of a more direct route home: his lover was working nearby and he hoped to see her.

The affair was exposed by a national newspaper and Mrs Simpson firmly believes it turned people opinion against her dad. After the news emerged youths shouted ‘murderer’ at Mr Heron as he walked in the garden of Aeolian house. Her sister, Jacqui, almost ended up in a fight in a nightclub after nasty things were said about her beloved dad.

And yet having an affair does not make anyone a murderer. Mr Heron does not deny the affair but will not talk about it, expressing a noble desire for an innocent woman to be left alone, especially after 25 years. Mrs Simpson speaks only of her shock and disappointment when she was told.

Instead they focus on the overwhelming desire for the murderer to be caught, Mr Heron to finally have his named cleared and for an apology to come from Durham Police and the Crown Prosecution Service for the failed prosecution, a prosecution that failed because there was no evidence against him.

“All I want is my name to be cleared and whoever did it be caught,” he says. “Let him suffer. Ann was not just murdered, she was savagely murdered, it was brutal.

“I’m an 80-year-old guy now. I might have ten years of life yet and I want my name cleared and I want justice for Ann. Instead, the police destroyed my life.”

*Tomorrow read how Mr Heron’s life was destroyed once again, this time after being arrested and prosecuted for the murder of the woman he loved, a murder he did not commit.