The force confirmed in an email Monday evening that Cpl. Paul Johnston has voluntarily submitted his discharge papers, and that they've been accepted.
Johnston was one of four officers who investigated the deaths of six people gunned down in a high-rise apartment building in Surrey, B.C., in October 2007.
But in early 2011, the province's Criminal Justice Branch announced a special prosecutor was looking into allegations that an officer involved in the investigation had an inappropriate relationship with a witness.
Following an investigation by the Ontario Provincial Police, the special prosecutor approved 20 charges in June 2011 against Johnston, Sgt. Derek Brassington, Staff Sgt. David Attew and Cpl. Danny Michaud.
Johnston was charged with four counts related to breach of trust and obstruction of justice.
Also on HuffPost