The first teenage girl has been identified as having been driven to kill herself after domestic violence, as police chiefs blamed violent pornography and “toxic” influencers for being behind a rise in teen abuse.

Suicides after domestic abuse have outstripped homicides for the third year running, according to the Domestic Homicide Project, which records deaths in England and Wales after domestic abuse.

Last year, there were 347 deaths, including 150 from suicide and 125 domestic homicides.

Across the five-year dataset, victims were predominantly female (73%), and suspects predominantly male (79%). Over the five years, the project recorded 1,452 deaths in 1,410 incidents – 641 of these were domestic homicides, 553 were suicide after domestic abuse, 131 unexpected deaths, 86 child deaths and 41 deaths classified as “other”.

Of the suicide cases, 88% involved a history of domestic abuse perpetration known to the police prior to the victim’s death. There were 85 more deaths last year than previously, but this has been attributed to wider knowledge among police forces about domestic violence before homicide and suicide.

“There is a small but encouraging increase in charges for suicide after domestic violence,” said the assistant police commissioner in the Metropolitan police Louisa Rolfe.

Domestic violence incidents were growing the fastest in the 16- to 19-year-old age group, said Rolfe, with this year’s statistics including the first teenager to have been driven to kill themself after being a victim of domestic abuse.

Rolfe said the increase was being driven by the “impact of pornography”, with young people “more likely to access violent pornography”. She added that young men were more likely than older men to engage in strangulation during sex, which was “featured more commonly in online pornography”. She added: “There are toxic influencers online with attitudes to women which make me incredibly sad.”

Rolfe said these influencers have caused a “normalisation of domestic abuse being seen as normal and expected within a relationship. The toxic influencers spout all of this nonsense about men being superior.”

While the rise in reports of suicide linked to domestic abuse was mostly attributed to a wider understanding of the subject, Rolfe said this was not the case for teenagers, as child deaths were investigated thoroughly. She said domestic abuse among teenagers was an “escalating situation”.

Rolfe said policymakers should be “looking at social media and age controls” and added: “As a parent, the best resources I’ve found online are the child exploitation online protection service. They have little infographic videos that children can watch about online harms and risks. I’ve made my children watch them.”

Of the rise in reports of suicide linked to domestic abuse, Frank Mullane, the CEO of the charity Advocacy After Fatal Domestic Abuse, said: “We’ve been saying for some time that the suicides are higher than the homicides. We still don’t know how many women are killed as a result of domestic abuse, but this shows it is bigger than anyone has known.”

There has been no jury conviction in England after a case of suicide after domestic violence, which is charged under the crime of manslaughter. Mullane is calling for driving someone to take their own life after domestic abuse to be classed as a separate offence to raise awareness among juries and the public.

Rolfe said domestic abusers in suicide and homicide cases “work to undermine victims’ credibility with police, friends and family. We would like to see wider society recognise the signs of domestic abuse”.

It was hard to secure a conviction, she said, because “when your biggest witness is the victim who can’t present evidence, that is difficult”. She added: “The abusers present themselves to society as the good guy, the steady one. If the perpetrator is a clever, narcissistic manipulator, and our justice system wasn’t designed for these type of cases.”

Mullane said the statistics were a “wake up call to all senior leaders across all agencies” and that the police needed to preserve the scene of suicides after cases of domestic abuse and treat them as potential homicides.

Coroners, he continued, were often loath to consider domestic abuse after suicide and homicide: “Coroners’ officers are mostly run by men, and they are enacting 800-year-old laws. A lot of my job is challenging coroners.” He said police needed to be more alive to suspected homicides after domestic abuse. “A bad investigation can scupper the whole case. There needs to be much more professional curiosity into unexplained deaths.”

The numbers are likely to be an underestimate; research by a suicide prevention programme in Kent found about a third of all suspected suicides in the region between 2018 and 2024 were affected by domestic abuse.

If the numbers in Kent reflect the national picture, it could mean as many as 1,500 victims of domestic abuse are taking their own lives every year – up to 15 times as many as previously thought.