The Plymouth “incel” killer had his gun licence returned to him a only month ago after it was previously removed, it was revealed on Friday night, as police faced mounting questions over why he was free to own a weapon.

Jake Davison, 22, killed five people, including a three-year-old girl and his own mother, during a 12-minute rampage through a residential area before turning the gun on himself.

MPs and relatives questioned how Davison was able to legally hold a pump action shotgun despite mental health problems and a series of videos he posted online which espoused extreme misogynistic views.

On Friday night, the Independent Office for Police Conduct confirmed that they were investigating Devon and Cornwall Police’s decision to return Davison’s gun licence. It was taken from him in December 2020 following an alleged assault last September. It was returned to him in July.

It was claimed that he had the shotgun for sports use and had the licence reinstated after he attended an anger management course.

The trainee crane operator was a self-described “incel”, who are online groups of “involuntary celibate” men who blame women for their inability to find a partner. This is the first killing in the UK by a self-confessed incel, following massacres in other countries including the United States and Japan.

Davison’s first victim was his mother Maxine, 51. He then killed three-year-old Sophie Martyn and her adoptive father Lee, 43, before shooting dead Stephen Washington, 59, and Kate Shepherd, 66. He then turned the gun on himself. He also left mother and son Michelle and Ben Parsonage with life-changing injuries.