A ST Dogmaels woman has been jailed for life for murdering her mother.

Penny John, of Maes Dre, Union Terrace, St Dogmaels, and her son Barry Rogers, of High Street, Fishguard, were sentenced to life with a minimum jail term of 11 years after being convicted of murdering John’s mother and Rogers’ grandmother, 84-year-old Betty Guy, at her home in Johnston in 2011.

Sentencing John, 50, and Rogers, 33, at Swansea Crown Court, Judge Clive Lewis QC said the pair had “never accepted responsibility”.

A statement from Mrs Guy’s other daughter Lorraine Matthews read out in court, said she was shocked that a member of her own family was capable of committing such a “despicable act on an old lady”.

Betty Guy, she said, “loved life” and “was no way ill enough to warrant a mercy (killing)”.

“We grieved once over her death and now we have to go through a different grief,” she said.

Chief Inspector Steve Davies said: “The investigation into the actions of Barry Rogers and Penelope John took over two years and involved extensive inquiries and I would like to thank Mrs Guy’s family for their support and cooperation during this extremely difficult time."

Rogers and John killed Mrs Guy - his grandmother and her mother - because she was too old and suffered from ill health, the court was told.

John mixed sedatives - including her own sleeping tablets - with whiskey and gave the mixture to her mother in the early hours of 7 November 2011.

That failed to kill her, and Rogers, a former soldier, “finished her off” by placing a pillow over her face.

At first her death was believed to have been from natural causes and Mrs Guy’s body was cremated at Narberth just four days later.

But Rogers could not keep his mouth shut and over the coming years told various women, including his one-time wife, that he and his mother had killed her.

After they had been arrested, detectives devised a clever plan to trap them.

Although they were living at different addresses, police agreed to grant them bail as long as they both stayed at John’s home in Maes Dre, Union Terrace, St Dogmaels.

Officers drove them to the address to make sure they abided by the bail conditions.

By then, a listening device had been placed in the property and as soon as they walked through the door they began talking about what they had done.

It was five years after they had killed Mrs Guy and neither could remember if they had swapped mobile phone text messages that the police might be able to retrieve.

Rogers became worried his mother was “starting to crack” and urged her to stick to their story that Mrs Guy had died from old age.

But the jury saw through it.