Osage County Sheriff’s officers have asked for help to find a man who allegedly impersonated a police officer and assaulted a woman Saturday morning.

According to a news release from the sheriff’s office, the suspect is a white male, 6-feet tall with black hair and a slight build. He wore a gray shirt and blue jeans.

The man had pulled the woman over at 7:38 a.m. on Kansas Highway 31 east of Osage City. A passerby, who drove a blue Dodge Dakota truck, interrupted the assault, according to the news release.

The suspect drove a small, dark sedan, which had a light bar in the back window and flashing headlights.

Officers are also trying to find the witness who stopped the assault. Anyone who sees the suspect or who has information is encouraged to call local law enforcement, the sheriff’s office at (785) 828-3121, or the Osage County Crime Stoppers Hotline at 1-877-OS-CRIME.