O’FALLON, IL. — Detective Benjamin Callahan was promoted to sergeant during a joint promotional ceremony with O’Fallon-Shiloh EMS on Tuesday, June 17, 2025. The O’Fallon Police Department recognized Callahan for his service since joining the department in 2016.
Sergeant Callahan currently serves in the Criminal Investigations Division and is a member of the Major Case Squad of Greater St. Louis. He also participates on the SWAT Team as part of the Illinois Law Enforcement Alarm System’s Weapons of Mass Destruction Special Response Team.
In addition, Callahan advises the O’Fallon Police Explorer Post and is a member of the department’s Honor Guard. Prior to his assignment in Criminal Investigations, he served as a Field Training Officer and Senior Officer.
Before his law enforcement career, Callahan served more than eight years in the United States Marine Corps.
The department expressed confidence in Callahan’s leadership as he assumes command of a patrol crew.
During the same ceremony, Nick Fensom was promoted to EMS Supervisor.
