The Danforth gunman could have been both ill and evil: Robyn Urback

At the moment, there are no answers as tothe precise motive behind the horrific shooting that left two dead and 13 injured on the Danforth in Toronto Sunday night.

We have plenty ofinferencesandsomeclues. But in terms of clear, specific informationthat definitively explains why a man took a gun and tried to destroy the lives of people he's nevermet, and then killed himself we just don't have it.

There are plenty of theories, of course: it's radical Islam, or toxic masculinity, or too many guns, or too few guns, or the lack of mental health supports. This is how the discourse plays out in the aftermath of nearly every mass shooting or terror attack nowadays; it's one explanation, but not the other. It's become so routine, it's almost canonical.

• Faisal Hussain ID'd as gunman in deadly Danforth shooting spree
• 'No evidence' Danforth shooter Faisal Hussain connected to ISIS, Toronto police say

The impulse to categorize an act so unthinkable does make sense: if we can understand the specific reason why this happened, then perhaps we can make changes to ensure it doesn't happen again. The problem with this line of thinking is that it assumes the perpetrators of these mass atrocities can be neatly classified as just one thing. But seldom is that the case.

Radical Islam, for example, is steeped in misogyny. And there are clear links between domestic violence and mass shootings. Those who commit lone-wolfterrorist acts, in many cases, have a history of mental illness and instability (though the link is not necessarily causal) andthe availability of a gun in the home makes someone several times more likely to commit or be the victim of an act of violence.

The point here is that all of these factors the ubiquity of guns, predisposition to violence, history of mental illness, susceptibility to online radicalization, hatred of women can beinterconnected. Rarely (though certainly not never) do we come across someone whocommits an act of violence who is pure, unadulterated evil. In most cases, the underlying issues are numerous and interwoven, which can be unsettling when we justwantto believethe solution is one handgun-ban away.

Here's what we do know about the man who opened fire at strangers on the Danforth: he was a 29-year-oldnamed Faisal Hussain. According to a statement from his family, which was written with the assistance of a community organizer, Hussain struggled with "severe mental health challenges," including psychosis and depression, for which treatments were unsuccessful. A source told CBC Newshe was apprehended by authorities twice when he was under the age of 18 for issues related to mental health.

A source also told the Toronto Sun that investigators are looking at Hussain's "'support' for a website that was seen as 'pro-ISIL,'" as well as his reported staysin Afghanistan and Pakistan. The Globe and Mail reported that on Sunday night in the final moments of the attack,Hussaincame across a neighbourhood resident named Jaspal Singh and said, "Don't worry, I'm not going to shoot you." ISIS claimed ownership of the attack two days later.

Choose only one of the above two paragraphs and you can surely cajole yourself into a singular conclusion: either Hussain was sick, acting out in response to delusions, or he was evil, sparing a brown-skinned neighbour on his way to "target citizens of coalition nations," as ISIS stated in its claim of responsibility.

But it doesn't have to be an either/or. As has been noted repeatedly by those who research terrorism and radicalization, part of the ISIS strategy is of small-scale attacks carried out by lone wolves and those who are mentally unstable make for great recruits. That appeared to be the case with Martin Couture-Rouleau, who fatally mowed down Warrant Officer Patrice Vincent in Quebec in 2014, andwith Michael Zehaf-Bibeau, who shot and killed Cpl. Nathan Cirillo in Ottawa that same year.

For what it's worth, ISIS's ownership of the Danforth attack should be understood in the context of a terrorist organization grappling with its dwindling influence, having experienced massive losses in terms of both land and relevanceover the past few years. That is not to suggest it is a non-entity indeed, it just executed a series of deadly attacks in southwest Syriathat killed more than215 people but the dream of a global caliphate is pretty much kaput.

That eroding influence would explain why ISIS would, for example, falsely claim to have downed a U.S. warplane in Syria a couple of years ago, or rushed to take ownership of an attack at a Manila resort last year, or even claimed it was behind the mass shooting in Las Vegas back in October, though police have said there is no evidence of a connection.

• Gunman in Danforth shooting rampage, killed himself: police source

Police here have said the same in the early stages of theinvestigation into Faisal Hussain. It is of course possible that investigators looking intoHussain'sonline activities could find evidence he was influenced by ISIS propaganda. But that information would not somehow cancel out what we've been told aboutHussain's mental health, therefore rendering his act one of pure evil, rather than sickness.

The two can exist together: the poisonous product of a confluence of factors including personal tragedy, mental illness, political rhetoric, online indoctrination and the availability of weapons.

Understanding the various factors at play doesn't make what happened any less tragic, nor is it intended to galvanize sympathy for the perpetrator. But it should help us come to grips with what's actually going on when we attempt to make some sense of the utterly senseless. Regular people don't fit into neat little boxes; I'm not sure why we would think mass shooters do either.

This column is part ofCBC'sOpinion section.For more information about this section, please read thiseditor'sblogandourFAQ.