Calgary, Alberta: A recent graduate of the University of Calgary was booked for five people at a house party that the police chief called the worst mass slaying in the western Canadian city's history.

Matthew Douglas de Grood, the son of a 33-year veteran of the Calgary police force, picked up a large knife shortly after arriving at the party and stabbed the victims one by one shortly after 1 a.m. Tuesday, said police Chief Rick Hanson.

De Grood, 22, was charged with five counts of murder late Tuesday.