Police investigating Britain’s first mass shooting in more than a decade — which left six dead, including the gunman — said Friday the motive was unclear but there were no immediate signs that the crime was an act of terrorism, or connected to right-wing groups. One of the victims was a 3-year-old girl, police said.

Police identified the shooter as Jake Davison, 22, and said he had a gun license, but revealed few other details. Witnesses reported that he used a pump-action shotgun in his rampage on Thursday night, police said, though they wouldn’t confirm what type of weapon it was and whether it was the one Davison was licensed to use.

Gun crimes are rare in Britain, where there are strict firearm control rules.

Shaun Sawyer, chief constable for Devon and Cornwall police, told reporters that officers responding to multiple emergency calls at 6:11 p.m. arrived six minutes later at an address in Plymouth’s Keyham neighborhood, where Davison had shot and killed a woman who lived there. Police are investigating whether Davison and the victim were related, he said.

Davison then left the house and immediately shot and killed the girl and her male relative who were outside. 

Davison then shot and wounded two other people farther along the street. He went to a park where he shot a man who died at the scene, then shot a woman on a nearby street who died later in hospital, Sawyer said.

The girl was three years old and the other victims ranged in age from 33 to 66, the police force said later on Twitter.

“Hearing that one of the dead is a small child is utterly heartbreaking,” Plymouth Member of Parliament Luke Pollard tweeted.

Eyewitnesses reported that Davison shot himself before police arrived. Davison was licensed to use a gun last year and police are checking whether he had the license before then.

Sawyer said investigators are not sure what his motive was, but are not considering terrorism or any links to far right groups, though they’re keeping an open mind.

“Let’s see what’s on his hard drive, let’s see what’s on his computer, let’s see what’s on social media,” Sawyer said.

“We believe we have an incident that is domestically related that has spilled into the street and seen several people of Plymouth lose their lives in an extraordinarily tragic circumstance,” he added.

Davison appeared to post on YouTube under the name “Professor Waffle” in an account that has now been taken down, replaced by a notice saying it violated the site’s community guidelines. In a final 11-minute clip posted before the killings, “Professor Waffle” talks about how he was “beaten down and defeated by … life.”

He refers to difficulties in meeting women, struggling to stay motivated at working out and losing weight, and working as a scaffolder. Davison also briefly refers to “people who are incels” – online shorthand for “involuntarily celibate” – saying that while he wouldn’t describe himself as one, they are “people similar to me, they’ve had nothing but themselves, and then they’ve socially had it tough.”

Prime Minister Boris Johnson tweeted: “My thoughts are with the friends and family of those who lost their lives and with all those affected by the tragic incident in Plymouth last night.”

The incident marks the worst mass shooting in the U.K. in more than a decade. Britain’s last mass shooting was in June 2010, when taxi driver Derrick Bird killed 12 people in Cumbria, northwest England.