July 9, 2025
DUBUQUE COUNTY, Iowa - On July 1, 2025, the Dubuque County Sheriff’s Office (DCSO) requested assistance from the Iowa Division of Criminal Investigation (DCI) with an officer-involved shooting along Highway 151 near Cascade in Dubuque County, Iowa.
At approximately 4:30 a.m. on July 1, members of the DCSO, Dubuque Police Department, Iowa Division of Narcotics Enforcement, Monticello Police Department, and Jones County Sheriff’s Office conducted a traffic stop of a vehicle on Highway 151 north of the Highway 136 interchange. The traffic stop was related to a multi-jurisdictional investigation.
During the traffic stop, the suspect in this investigation, an adult male and sole occupant of the vehicle, displayed a handgun. Shots were fired, which resulted in a DCSO sergeant, and the suspect, being struck by gunfire.
The DCSO sergeant was transported to MercyOne Emergency Care in Dubuque, then to the University of Iowa Hospitals and Clinics. He was later released after being treated for a gunshot wound.
The suspect, identified as James Sherrill, 36, was pronounced deceased. Sherrill was from the Linn County, Iowa area.
The officers involved have been identified as follows:
Sergeant Adam Williams, 46, an 18-year veteran of the Dubuque County Sheriff’s Office;
Officer Chad Leitzen, 49, a 23-year veteran of the Dubuque Police Department;
and Officer Cole Millard, 42, a 2-year veteran of the Monticello Police Department.
This is an ongoing investigation. No additional information will be released at this time.
Upon the conclusion of the investigation, the DCI’s investigative findings will be reviewed by the Dubuque County Attorney’s Office and the Iowa Attorney General’s Office.
ABOUT THE IOWA DEPARTMENT OF PUBLIC SAFETY
The Iowa Department of Public Safety (DPS) is the largest law enforcement agency in the state. It includes seven divisions and several bureaus, all working together with local, state, and federal government agencies and the private sector to keep Iowa a safe place by following our core values: leadership, integrity, professionalism, courtesy, service, and protection. Divisions within the Iowa DPS: Iowa Division of Criminal Investigation, Iowa Division of Narcotics Enforcement, Iowa State Patrol, Iowa State Fire Marshal Division, Iowa Division of Intelligence and Fusion Center, Professional Development and Support Services Division, and Administrative Services Division. The Department of Public Safety is led by the Commissioner who is appointed by the Governor.
Iowa Department of Public Safety
215 E. 7th St.
Des Moines, IA 50319