CINCINNATI—A Mason man has been arrested by the FBI for possessing an unregistered destructive device.

James River Phillips, 20, was arrested today by the FBI Cincinnati Field Office’s Joint Terrorism Task Force (JTTF) following federal court-authorized law enforcement activity at locations in Mason, Oxford, and Liberty Township, Ohio.

“The FBI’s Joint Terrorism Task Force arrested James River Phillips after he allegedly possessed a dangerous destructive device,” stated FBI Cincinnati Special Agent in Charge Elena Iatarola. “The FBI and our partners worked together to ensure his actions were stopped before there was any risk to public safety.”

According to the criminal complaint, Phillips is believed to have possessed an Improvised Explosive Device (IED) that was discovered by a Lebanon Police Department patrol officer on September 22, 2024, at an outdoor sports complex. The device was collected by the Butler County Bomb Squad and the components were tested.

Charging documents detail that the FBI’s Joint Terrorism Task Force was able to identify Phillips as the primary suspect who left the device at the sports complex. The JTTF has also been able to connect Phillips to other incidents where he is alleged to have possessed and detonated potential explosives.

The FBI is being assisted in this case by the Lebanon Police Department, Warren County Sheriff’s Office, Butler County Sheriff’s Office, Mason Police Department, Oxford Police Department, Ohio State Highway Patrol, Dayton Police Department, and the U.S. Bureau of Alcohol, Tobacco, Firearms & Explosives (ATF). Deputy Criminal Chief Emily N. Glatfelter with the U.S. Attorney’s Office for the Southern District of Ohio is representing the United States in this case.

A criminal complaint merely contains allegations, and defendants are presumed innocent unless proven guilty in a court of law.