A Canadian teen who killed eight people in one of the country’s worst mass shootings frequented the same gory websites that American mass shooters have been known to visit leading up to attacks in the U.S., investigators found.

Jesse Van Rootselaar opened fire on Feb. 10 at a home and a school in northeast British Columbia. The 18-year-old, who was born male and identified as a woman, left eight dead and dozens wounded before taking her own life. The attacks at Tumbler Ridge, about 700 miles north of Vancouver, are among the worst seen in America’s northern neighbor, where gun laws are stricter and mass shootings are a rarity by comparison.

The teen’s online activity "displays a fascination with violence and weapons," according to an Anti-Defamation League report shared on Feb. 12. The anti-hate group has a team dedicated to investigating hate speech online and mass shooters’ online history. Van Rootselaar espoused admiration online for other shooters and was active on WatchPeopleDie, a forum where users share images of torture, rape, beheadings and other violence.

The website has been a known destination for American school shooters, including in Wisconsin, Tennessee and Colorado.

"It's time for people to understand the connective tissue between incidents of children killing children around the world — and that connective tissue is websites like WatchPeopleDie and other gore platforms," Oren Segal, the ADL’s senior vice president of Counter-Extremism and Intelligence, said to USA TODAY in a statement.