I remember the author of the Universal Declaration of Human Rights, the late John Humphrey, explaining to me at the time that the reason that document and similar UN documents included freedom of thought was that the technology of the day couldn't attack it. Intent still remains, for the most part, outside the range of information technology collection. One's intent cannot be gauged.
However, repeaters can be identified and denied access to Canada. The other group, individuals who've had contact with law enforcement either in Canada or overseas, would be identified and denied access to Canada. That's a powerful tool. Could it have prevented the death in that particular case? Possibly. If the fellow were a repeater, yes. If the fellow were on the grid with a criminal background, yes.
But I must lay some element of blame with the Canada Border Services Agency, the people responsible for enforcing a person's removal from Canada. To date, to my satisfaction at least, it has not been explained why they took years to remove that fellow from Canada. He was on our grid.