Acting Insp. Ryan Ayliffe says officers will be looking into any communications the man had with people before the killings.
The Calgary Herald has reported that the suspect, Matthew de Grood, sent disjointed text messages to his family before showing up at a house party where five people were stabbed.
The paper quoted an unnamed officer close to de Grood's father saying the family was worried de Grood might commit suicide that night.
De Grood's father is a senior officer with Calgary police.
De Grood faces five counts of first-degree murder and is undergoing a psychiatric assessment while in custody.