A grieving son has appealed for information to find his mother’s killer after the 30th anniversary of her shocking murder.

The body of 44-year-old Ann Heron was found in a pool of blood in the living room of her large detached home near Darlington on August 3 1990.

It remains County Durham’s only unsolved murder in the last 70 years.

Ms Heron, the wife of a local businessman, had been sunbathing in her garden at Aeolian House earlier on that warm afternoon.

Her husband Peter Heron was charged with her murder in 2005 but the charges against him were dropped.

Now, 30 years after her death, her son Ralph Cockburn has made a heartfelt appeal for information.

It comes as Durham Police said they were using advances in forensic technology to review material from the scene.

Mr Cockburn, a 56-year-old former detective, said: “After all this time, we still do not know who did this to mum, and why they did it.

“If someone knows who did this and is withholding vital evidence, then I would urge them to rethink where their loyalties lie and do the right thing so my sister and I can finally get justice for mum.”

He added: “Mum was loved by everyone who knew her and nobody had a bad word to say about her.

“She was the softest person you could ever meet and loved animals and children.”

Mr Cockburn said: “She has five grandchildren, three of which she never got the chance to meet, and four great-grandchildren that she has also never met.

“I think that is the saddest part, as she never got the chance to see them grow up.

“You watch these things happen on TV and think that it will never happen to you, but it did. And somebody out there knows who did it, and why.”

Detective Inspector Andy Reynolds, from Durham’s Major Crime Team, said: “We are actively pursuing forensic inquiries using advances in technology in the hope of identifying evidence to prove who is responsible.

“If somebody is reading this and knows who killed Ann Heron, then please do the right thing and come forward.

“Her family deserve closure and she deserves justice.”