30 July 2012 Last updated at 11:48 ET

David Wyn Jones admits killing wife and son at Tremadog

David Wyn Jones is being held in hospital under mental health provisions [Pic: Daily Post]

A man has pleaded guilty to stabbing his wife and their two-year-old son to death at their home in Gwynedd.

At Caernarfon Crown Court, David Wyn Jones admitted the manslaughter of his wife Suzanne, 34, and son William near Tremadog on 30 March.

The Crown Prosecution Service accepted a plea of diminished responsibility, and the case has been adjourned until a later date for sentencing.

Jones is being held in hospital under mental health provisions.

A police investigation showed he had been the subject of delusional behaviour in the time leading up to the deaths.

"The defendant was a person of previously good character. There is no history of domestic violence against his wife or his child," said the prosecution team.

Suzanne Jones, 34, and her son William two, were found at their home

Enormous tragedy

"He was not under the influence of alcohol or drugs at the time of the offence. There was no rational motive for what he did."

The prosecutors said there was convincing evidence from two psychiatric experts that Jones suffered from a delusional disorder.

"There is no public interest in seeking a verdict from a jury in respect of murder," they added.

Judge Merfyn Hughes QC said he approved of the prosecution's decision to accept the plea, and said it must have been a difficult decision bearing in mind such an enormous tragedy.