[2] On 12 August 2021, Jake Davison had a physical altercation with his mother, Maxine, during which he reportedly grabbed her by the throat and prevented her from leaving a bedroom in their house on Biddick Drive in the Keyham area of Plymouth.

[11][12] Next, he shot through the front door window of a neighbouring house, injuring a 53-year-old woman and her 33-year-old son,[13] before shooting and killing a 59-year-old man in a nearby park.

[15] Davison then walked down Royal Navy Avenue, and went to Henderson Place, where, at 18:13, he shot and fatally wounded a 66-year-old woman outside a hairdresser's and remarked to a passing resident that there was "nothing to worry about, mate".

[17] Devon and Cornwall Police stated that officers attended the scene within six minutes of the emergency calls and found the bodies of Davison and four of the victims.

A CSW employee raised concerns with their manager that a Prevent referral might need to be made; however, this never occurred as there was "no evidence [Davison] was talking to people who could take advantage of him".

[27] He was a regular visitor to Shetland where he spent long periods of time with his mother's relatives, including his two older siblings; it was there that initial concerns were raised about his mental state.

[29] A close source to the family said that Davison had recently deteriorated after suffering from mental health problems for most of his life, and that his mother was "begging for help from the authorities but nobody did a welfare check".

[31] Davison applied for a shotgun certificate in July 2017, in which he declared autism and Asperger syndrome on the form and gave officers permission to contact his GP.

[25][33] Police had removed his shotgun and licence in December 2020 following an assault allegation described as "a row with two youths",[34] but the weapons were returned in early July 2021,[35] a month before the killings.

"[41][9] Davison used Reddit to share hostility and resentment towards his mother, who had repeatedly attempted to obtain – and persuade him to receive – treatment for his mental health.

[43] Davison became interested in weightlifting and bodybuilding during the final year of his life; his belongings had 'taken over the house' with him having a bedroom, a computer room and had set up his gym equipment in the lounge.

[58] Ian Arrow, the senior coroner for Plymouth said that "There was a serious failure by Devon and Cornwall Police's firearms and explosive licensing unit in granting and later failing to revoke the perpetrator's shotgun licence.

The IOPC investigated why Davison had a shotgun licence despite concerns around his mental health, and the senior coroner asked the office to examine the case of Michael Atherton who in 2012 killed his partner, her sister, her niece and himself, having had a history of domestic abuse and self-harm threats.

[64] On 6 October 2021, the IOPC issued disciplinary notices to two members of Devon and Cornwall Police over their handling of Davison's certificate for his shotgun, which he had claimed to use for clay pigeon shooting.

[65] On 15 August 2021, the British government announced that it would issue guidance to require police to investigate social media posts of firearms licence applicants and current holders.

[66][67] Before the new guidance is published, the Home Office asked all police services in England and Wales immediately "to review their practices and whether any existing licences need to be looked at again".