https://www.cbc.ca/news/canada/nova-scotia/ns-shooting-new-details-1.5564508
“Monday's news release also confirmed that the RCMP behavioural analysis unit is conducting a
psychological autopsy of the gunman — an in-depth study that analyzes his personality, his past behaviour and his interactions with others — in hopes of better understanding his motivations.
By interviewing friends, family and acquaintances, a psychological autopsy can provide insight into someone's mental and emotional state, as well as any patterns of abuse, said Jim Van Allen, who used the investigative technique in his past role managing the Ontario Provincial Police's criminal profiling unit. He trained and worked closely with RCMP.
Many violent crimes end up having "multiple motivations and overlapping motivations," he said, and abusive relationships are a common warning sign.
"Sometimes, you might see this coming, but nobody did anything to prevent it. Or, you get to look at the significance of the sequence of events and that might help you determine what was most causative in leading up to the person's decisions to carry out the behaviour that they did," Van Allen said.
"Everybody deserves an explanation, the best possible explanation the police can give. And I believe the psychological autopsy will help provide some of those answers to the people that want to know and deserve to know." .....”