A gunman shot dead five people after a row with his mother, an inquest has heard.

Jake Davison, 22, killed his mother Maxine Davison, 51, at her home in Plymouth before going outside and shooting dead four others in a 12-minute attack on the evening of August 12.

Three-year-old Sophie Martyn and her father Lee, 43, were shot dead in front of horrified onlookers as they walked their pet dog in Biddick Drive.

Davison then shot Stephen Washington, 59, in a nearby park, before shooting Kate Shepherd, 66, on Henderson Place.

The apprentice crane operator then turned the gun on himself before armed officers reached him.

During a 10-minute hearing on Thursday, Ian Arrow, senior coroner for Plymouth, Torbay and South Devon, formally opened the inquests into Davison’s victims and received evidence from police of identification and the brief circumstances of their deaths.

Detective Steve Hambly, the senior investigating officer, told the hearing all five had died from shotgun wounds and the results of histology and toxicology tests were pending.

He said Mrs Davison, a former trawler woman, had died at her home address in Biddick Drive, in the Keyham area of the city.

“The circumstances of her death are that Maxine sustained fatal gunshot wounds following an argument with her son,” he told the court.

“Police are not looking for any other persons in connection with Maxine’s death. On present evidence the medical cause of death has been ascertained as shotgun wounds to the torso and head.”

Mr Hambly said Mr Martyn, a married carpenter, was shot dead in Biddick Drive.

“The circumstances of his death was while walking with his daughter Sophie and the family dog, Lee was fatally shot by an assailant who was not known to him,” the officer said.

“The police are not looking for any other persons in connection with Lee’s death.

“By present evidence the medical cause of death has been ascertained as gunshot wounds to the torso and head.”

Referring to Mr Martyn’s daughter, the detective went on: “Sophie died on Biddick Drive on August 12 and the circumstances of her death are while out walking with her father Lee and the family dog, Sophie was fatally shot by an assailant who was not known to her.

“Police are not looking for any other person in connection with this evidence.

“On present evidence the medical cause of death has been ascertained as shotgun wounds to her head.”

The hearing was told Mr Washington, who was a carer for his wife, was shot while out walking his dogs in parkland close to Biddick Drive.

Mr Hambly said: “Whilst out walking his dogs, Stephen was fatally shot by an assailant not known to him. Police are not looking for any other persons in connection with Stephen’s death.

“On present evidence the medical cause of death has been ascertained as shotgun wounds to the chest.”

The final victim of Davison’s rampage was Katherine Shepherd, a married artist, who was fatally shot on Henderson Close.

Mrs Shepherd, who was known as Kate, was taken to Derriford Hospital where she died that evening, the inquest heard.

“The circumstances of her death are that Katherine was shot by an assailant not known to her while walking along Henderson Place,” the detective said.

“Katherine received immediate medical attention and was conveyed to Derriford Hospital. Despite best efforts of medical staff Katherine sadly passed away.

“The police are not looking for any other persons in connection with Katherine’s death. On present evidence the medical cause of death has been ascertained as shotgun wounds to the abdomen.”

In a separate five-minute hearing, the coroner opened and adjourned the inquest into the death of Davison.

Mr Hambly told the inquest: “Jake Davison died on Henderson Place. The circumstances of his death are that following an argument with his mother, Jake fatally wounded his mother.

“Jake then went along several different roads and fatally wounded another four victims, wounding and injuring two more, then taking his own life.

“The police are not looking for any other person in respect of this incident. On present evidence the medical cause of death has been ascertained as shotgun wounds to the head.”

The inquest heard the police investigation was looking at events on the evening of August 12, while the IOPC inquiry would consider how Davison came to legally own a shotgun.

Mr Arrow asked Det Insp Hambly to speak with the IOPC about considering any changes made by the Home Office or the former Association of Chief Police Officers following the case of Michael Atherton in County Durham in 2012.

Atherton, 42, shot himself, his partner Susan McGoldrick, her sister Alison Turnbull and Ms Turnbull’s daughter Tanya on New Year’s Day.

The coroner adjourned all inquests and fixed a provisional date for pre-inquest reviews on December 9.

As well as the coroner’s investigation, two other inquiries are already under way into the shootings.

The Independent Office for Police Conduct (IOPC) is examining the decision by the Devon and Cornwall force to return Davison’s shotgun certificate and weapon to him just weeks before the killings after they were seized following an allegation of assault.

The National Police Chiefs Council is also leading an investigation, in conjunction with the local police and crime commissioner, into the force’s firearms policies and procedures.

Meanwhile, the Government will be introducing new statutory guidance, including asking doctors to undertake medical checks on anyone applying for a licence, as well as inquiries into social media usage.

The Home Office has previously asked all police forces in England and Wales to review their current firearm application processes, as well as assess whether they need to revisit any existing licences.

Davison received mental health support during the coronavirus lockdown and had been in contact with a telephone helpline service in Plymouth run by the Livewell Southwest organisation.

Social media usage by Davison suggested an obsession with “incel” culture, meaning “involuntary celibate”, as well as an interest in guns and the US.

Reports have suggested Davison’s mother had been struggling to get help for her son, having become concerned about his mental health.