The Tooze murders: Why the Llanharry farm killings remain a mystery 30 years on

The murder of Harry and Megan Tooze at their seemingly idyllic little farm near the village of Llanharry is still the subject of speculation and rumour exactly thirty years after it happened.

How could an elderly couple, living an uneventful retirement on a smallholding, be shot to death as they prepared to eat lunch on a summer's afternoon in a seemingly motiveless attack?

Of course, there must have been a motive, however trivial, it's just that we have yet to piece together what exactly happened at Ty Ar Y Waun (Meadow Farm) all those years ago. 

In 1993, the police thought they had the story all worked out. Jonathan Jones, the boyfriend of the couple's only daughter Cheryl, had killed his prospective in-laws for their inheritance.

Jones – they said – had travelled from his home in Orpington in Kent, probably by train, then caught another before making his way across the fields, armed with a shotgun to commit the murders.

The murdered couple, it was claimed, had even got the "best china" out for their soon-to-be son-in-law, thinking that he had called on them to ask for Cheryl's hand in marriage. Indeed, Jonathan Jones' partial thumb print had been found on a saucer.

Faced with no other explanation, a jury convicted him of the murder and he was jailed for life.

The problem was the story just didn't hang together.

There was no forensic evidence linking him to the murders, even the partial fingerprint on the saucer had an innocent explanation. Even the trial judge acknowledged this when, after the verdict, he took the unprecedented step of writing to the Home Secretary expressing his doubts at the guilty verdict.

The judge wasn't alone.

The conviction was thrown out with lightning speed just three years later by the Court of Appeal. Jonathan Jones was a free man.

He went on to marry Cheryl, and they have a son James – but life has been difficult for the family ever since.

So what did happen at the farm on that Monday morning in July?

The couple were seen late morning arriving back from their usual shopping trip. There seems little doubt that a "best china" cup and saucer had been set on the table, so who was the mystery visitor that warranted a special welcome?

It is known that Harry had made an appointment at a local solicitor vexed about a contested family will. Was the caller unexpected?

The lunch that had been prepared but never eaten would suggest that it wasn't a planned visit.

Neighbours reported hearing gunshots at about 1.30pm in the afternoon but thought that it was just Harry shooting rabbits, as he often did, to keep them away from his vegetable plot.

There have been suggestions that the Toozes could have been the victims of serial killer John Cooper, who murdered at least four people in Pembrokeshire during the 1980s.

There are clear similarities but also differences and so far detectives have not found a link to Cooper. 

Over the years, there have been several renewed attempts to find the answers that make sense of it all.

It is always the same with these cases. It is difficult to work out which details about the Toozes' lives are significant to the case and which are just ordinary moments that seem more curious than they actually are.

Time is also an enemy now with peoples' memories and recollections fading after thirty years.

This is why today's announcement by South Wales Police is potentially very significant.

They are beginning a forensic review of the case which will look at many of the original exhibits that have been kept in storage to see if the latest forensic science can find any traces of the killer.

The force has turned to world-renowned scientist Dr Angela Gallop to advise on the case.

Those who are familiar with the Lynette White murder investigation will know her name.

It was Dr Gallop who found the tiny droplets on blood in the murder scene which led to the conviction of Jeffery Gaffor for the murder.

Over the years she has helped solve some of the most baffling cases, including the double murders in Pembrokeshire, finding the forensic clues where others have failed. The hope is she can bring some fresh thinking to these unsolved murders.

After such a long time only science can now bring the answers.

This case has been with me all my career, as the murders happened just three weeks after I joined ITV Wales.

The murders were a huge story dominating the headlines night after night. Over the years, I got to know both Cheryl and Jonathan.

I was with them in London when Jonathan was freed at the Court of Appeal.

Today they have cautiously welcomed the review of the case and are heartened by Dr Gallop's involvement but like all these cases there is a long road ahead and the police and scientists will need a little luck.

Who knows what the exhibits will offer up after all this time, but perhaps this is the best chance to date to explain the dreadful events at Meadow Farm.

Watch a special report by Jonathan Hill on Wales at Six on the 30th anniversary of the murders.