Two additional individuals have been arrested in connection with a homicide investigation in Clarence-Rockland, bringing the total number of accused in this case to five.
On Saturday, May 17, 2025, at approximately 5:30 p.m., officers from the Russell County Detachment of the Ontario Provincial Police (OPP) responded to a report of a body discovered in the Ottawa River, near Dallaire Street. The deceased was identified as Robert PREVOST, 63 years old of Clarence-Rockland, who was reported missing in early March 2025. He was last seen at his home on Laurier Street in early February 2025. Robert’s death was deemed a homicide.
Since June 2026, three individuals were previously arrested and charged in connection with this investigation. As a result of the ongoing investigation, two additional individuals have now been arrested and charged.
On Friday, September 11, 2026, Mathew BLAKE, 23 years old, of Arnprior, was arrested and charged with the following Criminal Code (CC) offences:
- Second degree murder, section 235(1)
- Indignity to a dead body, section 182(b)
- Obstruct peace officer, section 129(a)
The accused remains in custody and is scheduled to appear before the Ontario Court of Justice in L’Orignal on Friday, October 2, 2026.
On September 17, 2026, Sebastien BOUCHER, 47 years old, of Rockland was arrested and charged with the following CC offences:
- Obstruct peace officer, section 129(a)
- Obstruct Justice, section 139(2)
- Accessory after the fact, section 240
The accused remains in custody and is scheduled to appear before the Ontario Court of Justice in L’Orignal on Thursday, September 17, 2026.
The Russell County OPP Crime Unit is continuing the investigation, under the direction of the OPP Criminal Investigation Branch (CIB), in conjunction with the Office of the Chief Coroner and the Ontario Forensic Pathology Service. Assistance has been provided by OPP Forensic Identification Services, Emergency Response Team, Canine Unit, Aviation Unit, Underwater Search and Recovery Unit and the Snowmobile, All-Terrain Vehicle and Vessel Enforcement team.
Anyone with any information regarding this investigation should contact the Russell County OPP at 1-888-310-1122. Should you wish to remain anonymous, contact Crime Stoppers at 1-800-222-8477 (TIPS) or ontariocri