Calgary police say a significant part of their investigation into this week's mass murder of five young people will focus on whether the suspect was suffering from mental illness.
Acting Insp. Ryan Ayliffe said Thursday that officers will be looking into any communications Matthew de Grood had with people before the killings.
The Calgary Herald has reported that de Grood sent disjointed and confusing text messages to his family before showing up at a house party that ended in bloodshed.
The newspaper quoted an unnamed officer close to de Grood's father saying the family was worried the 22-year-old might commit suicide that night. His mother called police and his father went looking for him.
De Grood's father is a senior officer with Calgary police.
Ayliffe said he couldn't divulge the content of such a message.
"The devices (de Grood) used, the people that he might have contacted and the actual content of that message certainly forms a significant part of this investigation."
He told reporters any communication de Grood had with people before the party might help explain his state of mind and also provide clues as to a motive. Investigators have said it appears the victims did nothing to provoke the attack.
De Grood, who faces five counts of first-degree murder, is undergoing psychiatric assessment while in custody. He is to appear in court on Tuesday.
Police have said de Grood finished his late shift at a grocery store before going to the party, which was being held to celebrate the last day of classes at the University of Calgary. He was an invited guest and mingled with some of the 20 people there before allegedly grabbing a knife and stabbing people one by one.
Police found three people dead inside the home. An injured woman, also in the home, and a wounded man on the front lawn were taken to hospital but died.
The victims have been identified as Zackariah Rathwell, 21, Jordan Segura, 22, Josh Hunter, 23, Kaitlin Perras, 23, and Lawrence Hong, 27.
The City of Calgary has lowered all flags at its municipal buildings and said they will remain at half-mast until sunset on the day of the last funeral for the victims.
The first service has been set for Segura on Monday.
The University of Calgary says students affected by the tragedy can defer final exams until May or June.