The 18-year-old suspect in a high school shooting in British Columbia had previously created a mass shooting simulator on the gaming platform Roblox, it has been revealed.

The simulator, set in what appeared to be a virtual shopping mall, allowed users – represented as Roblox-style avatars – to pick up weapons and shoot other players, 404 Media reported on Thursday.

Users first identified the suspect’s Roblox account and game on Kiwi Farms, a site known for doxing and trolling. After the shooting on Wednesday, Canadian police identified the suspect as Jesse Van Rootselaar.

In a statement to the Guardian, Roblox said: “We have removed the user account connected to this horrifying incident as well as any content associated with the suspect. We are committed to fully supporting law enforcement in their investigation.”

The California-based company added that the “Mall experience” was accessible only through Roblox Studio, a separate app used by developers to create games. As a result, the simulator recorded just seven visits.

Roblox also said it uses a combination of AI and a team of safety specialists to review content that is uploaded to its platform before it is shown to another user.

Wednesday’s attack – one of Canada’s deadliest school shootings since the 1989 École Polytechnique massacre when a gunman killed 14 women – left nine people dead in Tumbler Ridge, a small coalmining community.

The victims included a teacher, five students, the suspect’s mother and her stepbrother. The suspect, who reportedly had a history of mental health issues, was found dead from a self-inflicted gunshot wound.

This isn’t the first time Roblox has been criticised for its content. The platform allows its millions of users to create and share their own video games – many of them benign, featuring cartoon fish and camping trips.

However, it has also allegedly made Jeffrey Epstein-themed content available to children, and is facing a lawsuit in California for facilitating the sexual exploitation and assault of minors.

The links between violent video games and mass shootings have been long-debated and remain inconclusive, with large studies finding at most a small correlation between gaming and real-world aggression.

However, though games may not cause violence, recent incidents underscore the growing trend of “gamified violence”: extremists adopting elements of video game design in the context of real-world attacks.

This is becoming increasingly common. The attackers in the 2019 mosque shooting in Christchurch, New Zealand, broadcast their massacre on Twitch, a platform that allows users to livestream themselves playing video games; as did the shooter in the racially motivated attack in Buffalo, New York, in 2022.