The Plymouth gunman's online activity revealed a clear disdain for his mother, whom he called “vile” and "disgusting" in the lead-up to his deadly attack.
Jake Davison, 22, shot and killed his 51-year-old mother Maxine Davison, also known as Maxine Chapman, at a house in Biddick Drive in the Keyham area of the city on Thursday evening.
He then strode out into the streets and opened fire, killing four others including a three-year-old girl and her dad, wounding two more victims, and then turning his gun on himself.
His social media activity will form a key part of the investigation as officers attempt to establish a motive for the attack, police say.
His interactions online reveal Davison had spiralled into the depths of the angry 'incel'- involuntarily celibate - online community.
He complained about his lack of success of women, labelled himself ugly, and spewed misogynistic rants on platforms including YouTube and Reddit.
The killer also only spoke about his mother negatively in the lead-up to his deadly spree, calling her “abusive”, “disgusting” and “vile”.
His posts laid bare his interest in guns, America, and bodybuilding attempts in a bid to make himself more attractive to women.
Davison brought up his mother on several occasions in different Reddit posts while complaining about the state of his life.
In one post, from a few months ago, he spoke of living in a “council/government house” and not having to anyone to interact with apart from his “vile mother”.
In another, dated 10 days ago, he answered a question asking “What do incels think of their mother?” by saying “cant stand her” (sic).
A lengthy post from five days ago Davison spoke of his mother being “a great example” of a woman who never thinks she is the problem.
It went on: “She has never apologized in her life and very few women ever do for anything she genuinely believes she has been a great mother who ‘tried her best’.
“She has never taken responsibility for anything ever even when she was 100 percent in the wrong being horrible it was never her fault and because she is my mother rather then put up with her s*** i appeased her cleaned up said sorry to her even when it wasn’t my fault.
“But you best believe i will not tolerate this EVER with any other women that comes into my life her being both my mother who im forced to live with due to money reasons is the ONLY reason i put up with it.”
In another, from a month ago, he bemoaned having to live with his “disgusting abusive mother” for “years on end”.
Davison also engaged with a number of gun-related videos and accounts through his YouTube channel, named Professor Waffle.
A lengthy Reddit post from his account further demonstrates his obsession with firearms.
In the comment, which was posted around three weeks ago, Davison declared “mass shootings are new phenomena that cannot be directly blamed on guns”.
Devon and Cornwall Police confirmed he was a licensed gun holder, as the force referred itself to a police watchdog on Friday.
It was revealed today that Davison almost lost his firearm licence over an assault allegation made last September - but it was handed back to him three months later.
In what appeared to be Davison’s final YouTube upload before Thursday’s atrocities, he spoke of being “beaten down” and “defeated by life”.
“I’m surprised I even made it this far to be honest,” he said, adding, “for the most part it’s just been me against the world.”
Another of his Reddit posts read “How to get over feeling its too late and the best years are behind me.”
YouTube took down Davison's YouTube account on Friday, and his Facebook page appeared to have been suspended.
