Devon and Cornwall police are facing a criminal investigation into alleged breaches of health and safety rules before the Plymouth mass shooting.
Jake Davison, 22, killed his mother, Maxine, 51, after a row, before shooting dead four others in a 12-minute attack in the Keyham area of the city in August last year.
He then turned the pump-action shotgun on himself before armed officers reached him.
The shotgun and licence were returned to him weeks earlier by police, who had seized it in 2020 after Davison assaulted two teenagers in a park.
The Independent Office for Police Conduct (IOPC) said on Tuesday: “We can confirm we have begun an investigation into Devon and Cornwall police for potential breaches of health and safety legislation in the running of its firearms licensing unit prior to the mass shooting in August last year.
“At the conclusion of our investigation into the force’s granting of a shotgun certificate and later return to Jake Davison of a shotgun, we sought specialist legal advice and have since decided to conduct a criminal investigation.
“Our investigation will examine whether the office of the chief constable of Devon and Cornwall police, as corporation sole, may have committed any offences contrary to the Health and Safety at Work etc. Act 1974.”
Jim Nye, an assistant chief constable of Devon and Cornwall police, said: “The force has cooperated fully with the IOPC investigation, the coronial process and commissioned an independent review of the force’s firearms licensing procedures.
“We are aware of the latest developments from the IOPC investigation and continue to cooperate fully with them, while considering next steps the force may choose to take on this matter.
“The force notes this development is in its early stages and no determination in terms of potential corporate culpability has been decided.”
Police sources emphasised that no individual faced criminal investigation. A corporation sole is a legal entity consisting of a single incorporated office.
Three-year-old Sophie Martyn, her father, Lee, 43, Stephen Washington, 59, and Kate Shepherd, 66, all died on the evening of 12 August last year.
As part of the IOPC investigation, two members of staff have been served with gross misconduct notices, while an officer has been served with a misconduct notice.
At a pre-inquest hearing at Plymouth coroner’s court, Edward Pleeth, a barrister representing the IOPC, told the senior coroner Ian Arrow that the investigation would take some time but he believed it would not affect the inquests, due to begin in January.
Jason Beer KC, representing the force, said it was not seeking to adjourn the inquests in light of the development as the force had committed to providing prompt answers to key questions.
Social media usage by Davison, an apprentice crane operator, suggested he harboured extreme misogynistic and homophobic views, as well as an interest in guns.
A further pre-inquest review will take place on 19 December.
