ITV News UK Editor Paul Brand reports from a city still coming to terms with Thursday's shooting
The gunman's mother, named by police as Maxine Davison, is among five people killed by Jake Davison in the mass shooting in Plymouth.
A three-year-old girl shot by 22-year-old Jake Davison in the Keyham area has also been named as Sophie Martyn.
Two local residents, aged 53 and 33, were injured in the shooting, though it is not believed their lives are in danger.
Davison killed three others, including Sophie's adoptive father, Lee Martyn, aged 43.
Police have named the victims killed as:
Maxine Davison, also known as Maxine Chapman, aged 51, who was the gunman's mother;
Sophie Martyn, aged three, and her father Lee Martyn, 43;
Stephen Washington, 59;
Kate Shepherd, 66, who was injured at the scene and died later at Derriford Hospital.
The Independent Office for Police Conduct [IOPC] will investigate Devon and Cornwall Police over Davison’s possession of a shotgun and shotgun certificate, which were returned to him last month after being removed in September 2020 following an allegation of assault.
IOPC Regional director David Ford said mandatory referral had been received from the police force on Friday morning, relating to the shooting as well as “police contact with Jake Davison prior to the incident.”
This includes the force’s role and actions regarding firearms licensing, he said.
Mr Ford said: “We will examine what police actions were taken and when, the rationale behind police decision-making, and whether relevant law, policy and procedures were followed concerning Mr Davison’s possession of a shotgun.
“The investigation will also consider whether the force had any information concerning Mr Davison’s mental health and, if so, if this information was appropriately considered.
“It appears the force’s response to reports of the shootings was very prompt and having reviewed information currently available, we are not intending to investigate the Devon and Cornwall Police response to the shootings.
"This will be kept under review as more information emerges. However, the investigation will explore whether there was any causal link between the arrival of police and Mr Davison apparently shooting himself.”
Mr Ford added: “It has not yet been established whether the shotgun returned to Mr Davison was used in yesterday’s shootings.”
Jake Davison was allowed to own a gun, despite Britain having some of the strictest gun laws in the world:
In a statement earlier on Friday, Devon and Cornwall Police said the gun used by Davison was carried legally.
“As previously said by Devon & Cornwall Police, the firearm believed to have been used during the incident was legally held by the offender," it read.
"The circumstances surrounding that have now been subject to a mandatory referral to the IOPC by Devon & Cornwall Police. “Police continue to investigate 13 scenes within the cordon in Keyham, which is expected to remain in place throughout much of the weekend.”
Prime Minister Boris Johnson said the issue of how Davison came to legally own a gun should be “properly investigated” as he described the shooting as “absolutely appalling.”
Davison posted multiple lengthy videos of himself on YouTube under the name 'Professor Waffle.'
In one, he speaks about "love" being for "the young." He says: "I know I'm still somewhat young and I hope I can make up for it but I have a feeling like I missed that boat. You can't ever make up for that."
YouTube has since confirmed an account belonging to Davison has been terminated from the platform, for violating its offline behaviour policy.
Facebook also confirmed that accounts belonging to the Plymouth gunman have been removed.
Paul Brand on the questions being asked of authorities
Davison had been an apprentice at Babcock International since August 2020.
Babcock CEO, David Lockwood, said: "I am shocked and deeply saddened by the events that have unfolded overnight in Plymouth and the deaths of six people.
"Our thoughts and condolences are with the friends and families of those involved in this tragedy. We stand with the city at this difficult time.
"As one of the largest employers in Plymouth, we are providing support and help for any of our colleagues who feel affected by this incident."
Earlier on Friday evening, Labour’s Luke Pollard, the MP for Plymouth Sutton and Devonport, urged the local community to gather for a candlelit vigil at 9pm on Friday in North Down Crescent Park, Keyham, to pay tribute to the victims.
“Today’s been another really grim and difficult day… it’s important that the community comes together,” Mr Pollard said in a video on Twitter.
“Keyham is an incredible community, I know that communities, not only in Keyham, but neighbouring in North Prospect, Ford and Stoke and Devonport will want to pay their respects as well… this park is big enough for us all.
“There will be no speeches, it will just be a moment for us to come together as a community for a quiet moment of reflection after a really grim and hideous 24 hours for our community.”
Mr Pollard urged those attending to bring a candle, adding if they do not have one “your mobile phone light will do as well.”
A large crowd gathered at the vigil to pay tribute to the victims of the Plymouth mass shooting.
People were seen laying down flowers and holding candles in North Down Crescent Park in Keyham to remember those who were killed by gunman Jake Davison. Dozens of tributes were placed on the grass.
Plymouth City Council said a minute’s silence will be held for the victims at 11am on Monday.