Police said Constable Grzegorz Pierzchala, 28, was killed Tuesday afternoon while responding to a vehicle in a ditch just west of Hagersville, Ontario, about 28 miles southwest of Hamilton.
Authorities have given no details on what happened in the shooting or speculated on a possible motive.
Thomas Carrique, commissioner of the Ontario Provincial Police, said Pierzchala had been with the force for just over a year and had recently been notified that he had passed his 10-month probation period.
Haldimand County Mayor Shelley Ann Bentley visited the shooting scene Wednesday with other community members to pay tribute to the officer.
“It is heartbreaking, disturbing, very upsetting for our community,″ she said. “These things just don’t happen in Haldimand County.″