“I can say that Jesse was born as a biological male who approximately six years ago began to transition to female,” Dwayne McDonald, the Royal Canadian Mounted Police (RCMP) deputy commissioner, said.
The shooting at the nearby home occurred first, then the suspect went to the school, McDonald said.
The victims at the school were a 39-year-old female educator, three female students, all aged 12, and two male students, one aged 12 and the other 13.
Authorities do not believe there are other suspects involved in the shootings.
Police said they had attended the suspect’s family home on multiple occasions over the past several years, with some calls related to mental health concerns.
Van Rootselaar was known to police, and “we’ve begun the process of reaching out to” the public health care system to “understand what interactions may have taken place,” British Columbia Premier David Eby told a news conference outside the Tumbler Ridge town hall late on Wednesday evening.
The suspect previously had a valid gun licence that had since lapsed, McDonald said.
Police said Van Rootselaar had dropped out of Tumbler Ridge Secondary School four years ago.