IPSWICH: A top Suffolk psychologist believes a twice convicted double-murderer may have been responsible for the deaths of an elderly brother and sister 35 years ago.

Dr Clive Sims, formerly the lead consultant forensic psychologist at Suffolk Mental Health Partnerships NHS Trust based at St Clement’s Hospital in Ipswich, has called for the investigation to be re-opened.

Dr Sims, who still lives in Suffolk, has questioned the verdicts reached by a jury inquest into the deaths of Griff and Patti Thomas, saying he thinks “they were unsafe”.

He also believes it is possible John Cooper – sentenced in May for two double murders in Pembrokeshire in the 1980s – could be connected to the siblings’ deaths.

The Thomases were found dead at their isolated farmhouse in Llangolman, in Pembrokeshire, in December 1976.

An inquiry concluded Mr Thomas, 73, had argued with the sister he had lived with for 70 years, before hitting her on the head with a blunt instrument and setting himself on fire.

Dr Sims has been asked to review the case following Cooper’s convictions and believes there are inconsistencies in the original findings.

In 1977 an inquest returned a verdict of manslaughter on Patti Thomas, and an open verdict for her brother.

Dr Sims believes the pair were killed by an intruder following a “botched burglary”.

He said: “I feel that there would be substantial evidence for looking at this case again as a cold case.”

Dr Sims added there are striking parallels to the murder of two of Cooper’s victims, siblings Richard and Helen Thomas, at their isolated farmhouse at Scoveston Park in December 1985.

He said: “There is an empty cash box, the bureau has been broken into, the back door is unlocked and certain aspects of it simply do not make sense.

“There are enough similarities between the crimes to suggest that he may at least be a suspect in this case.”

Dr Sims thinks it is likely Cooper was responsible for other serious crimes long before the Scoveston Park murders in 1985. Cooper was aged 40 at that time.

The doctor said: “It would be extremely unusual for someone to start that late in life on a criminal career, and to start with that level of violence.”

Dr Sims’ views were aired last night as part of a BBC Cymru Wales programme