The family of a man and his former wife who were killed by their mentally ill son have said they struggled for years to get him help.

William Warrington, 42, has admitted the manslaughter of Clive and Valerie Warrington by reason of diminished responsibility.

In a victim impact statement read during his sentencing hearing, the family said his health had been declining for a decade and blamed deficiencies in psychiatric care.

“Our worst nightmares were realised when the crimes were committed on March 2 because we could not have foreseen the events of that day,” the statement said.

“However, in the weeks prior our fears for the safety of the family have been communicated to the emergency services, Gloucestershire Police, Gloucestershire Health and Care NHS Foundation Trust.

“Our fears were confirmed when our parents were brutally murdered by our brother, William Warrington.

“The pain of losing our parents is immeasurable and we will carry it every day for the rest of our lives.

“We will forever be affected by the dramatic nature and preventable circumstances which we have been told will be fully investigated by a formal inquiry.”

The statement, read by prosecutor Anna Vigars KC, said Warrington had been ill for several years.

“William’s mental health has specifically been in decline over the past decade and accelerated due to a deficiency of support in the system,” they said.

“When he lost his mind, we lost our brother and then the ultimate tragedy: we lost our mother and father.

“We lost all confidence in the government agencies and systems responsible for managing and responding to mental health crises and domestic abuse.

“We firmly believe that he continues to pose a severe threat.

“The idea that you might one day be released is horrifying. Again, we are living in fear of our safety.”