TORONTO, Ont. – A preliminary hearing was underway, Monday, to determine whether a Toronto police constable will stand trial for murder.

Const. David Cavanagh was part of the Toronto guns and gangs raid in Etobicoke in 2010, when he shot a 26-year-old man in the back. The man died later in hospital.

Const. Cavanaugh was first charged with manslaughter. Later, the province’s Special Investigations Unit upgraded the charge to second-degree murder

This is believed to be the first time in history a Toronto police officer has been charged with murder in connection with an incident on the job.