"SOMEONE out there must know who did this to my mum and, more importantly, why.”

Those are the words of Ralph Cockburn who is still seeking answers to his mum's death 30-years after her body was found in her Darlington home.

Friday, August 3 1990 began as a normal day for Ann Heron.

The mother-of-three had spent the morning shopping in Darlington with a friend, before returning home to Aeolian House to sunbathe in her garden for the afternoon.

At around 6pm that evening, the 44-year-old’s body was discovered in her living room lying in a pool of blood.

Despite an extensive police investigation, which spanned a number of years and has been subject to a significant review, her killer has never been found.

Now, thirty years after her death, her son, Ralph Cockburn, has issued a heartfelt appeal to find his mother’s killer and give her family closure.

It comes as Durham Constabulary confirm they have been 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.”

“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,” he added.

“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.”

The only person arrested in relation to the murder remains Peter Heron, Ann’s husband, but charges against him were dropped in 2005 when the police discontinued the case.

He has vehemently denied all accusations, and on Monday in The Northern Echo, he said that the arrest had caused him to live under a cloud of suspicion.

He pleaded with Durham police to give him his day in court so the public could see him clear his name.

Mr Heron, now 85, lives between Sedgefield and Stockton, and his daughter, Debbie Simpson, said yesterday: “We welcome the ongoing examination by Durham police’s forensic staff, although we also note from their response on August 3 that other than the forensic examination, no active lines of enquiry are being pursued.

“We also echo Ralph’s comments regarding the distress this has caused and reiterate our appeal for anyone with any information that could lead to the identification of who was responsible for murdering Ann to come forward.”

Detective Inspector Andy Reynolds, from Durham Constabulary’s Major Crime Team, said: “The force carried out a major investigation into the murder of Ann Heron and the inquiry has already been the subject of significant review.

“While the person responsible remains unknown the case will never be closed.

“We are actively pursuing forensic enquiries 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.”

Please call Durham Constabulary on 101 with any information.

Alternatively, information can be passed on to Crimestoppers anonymously on 0800 555 111.