The mass shooting in Toronto Sunday night killed two people and injured 13 others. Monday afternoon, Canadian police identified the shooter as Faisal Hussain and refused to either confirm or rule out terrorism as a possible motive. But as I also noted Monday, Hussain’s family immediately put out a statement expressing sorrow for the victims and stating that their son had ongoing mental health problems.

Today, Reuters reports ISIS has claimed Hussain was “a soldier of the Islamic State and carried out the attack in response to calls to target the citizens of the coalition countries.” However, ISIS offered no proof to back up this claim. Meanwhile, CBC has confirmed that Hussain was involved with police twice before he was 18 over mental health problems:

Toronto police say they have “no evidence” that Faisal Hussain’s shooting rampage on the Danforth was connected to ISIS.

“At this stage, we have no evidence to support these claims,” said Toronto police Chief Mark Saunders.

“We will continue to explore every investigative avenue including interviewing those who knew Mr. Hussain, reviewing his online activity, and looking into his experiences with mental health,” he added…

CBC News has learned from a source close to his family that Hussain was apprehended twice by police while he was under 18. A police source said that Hussain’s prior contact with authorities involved mental health problems.

But there’s one other wrinkle in this story. CBS News reported yesterday evening that Hussain had been watching ISIS videos on his computer:

A law enforcement source told CBS News that Faisal Hussain visited Islamic State of Iraq and Syria (ISIS) websites and may have expressed support for the terrorist group. They were looking into whether Hussain may have lived at one time in Afghanistan and possibly Pakistan, the source said. There is no indication that Hussain was directed by ISIS to carry out the attack.

So there are two competing but not mutually exclusive motives being offered here. The evidence for a history of mental problems appears to be confirmed both by the family and by the source speaking to the CBC. As for the ISIS link, that remains unconfirmed. One of the best analysts of ISIS’ statements is reporter Rukmini Callimachi. Here’s her breakdown of what ISIS is claiming in this instance:

So, given what Callimachi says in #7, combined with what CBS News reported yesterday, there is at least some reason to think this is a case of a self-radicalized individual who was inspired but not necessarily directed by ISIS. That could be true even though he also had serious pre-existing mental problems. But none of that has been confirmed yet.

Here’s a Fox News report on the ISIS claim of responsibility: