Thousands of drives travel Wilson Dam Road in Muscle Shoals each day, so it's not unusual to see police officers patrolling the area.
When Grace Stockton saw blue lights behind her Thursday, she knew she had not been speeding.
"He got out and came up to my window, and I kept my door locked and just cracked it a little bit," she said.
Stockton noticed the man was wearing all black. He appeared to be in his late 40s and was wearing a gun belt and some sort of two-way radio.
"He said 'I ran your tag and you have a warrant out for your arrest,'" she said. "And I said 'Well this is my mom's car that I'm driving, and I'm pretty sure that neither one of us have a warrant."
Stockton said the man mumbled something into his radio and walked away. Before he left, she noticed a badge on his shirt that seemed fake. The last name "Johnson" covered it.
"In the moment I didn't really know what to do," she said. "I was kind of freaking out because I knew I didn't have a warrant. The whole thing was really creepy."
Surrounding law enforcement agencies in the Shoals say Stockton's report is the only one they have of someone impersonating an officer and pulled over vehicles.
Muscle Shoals police encourage anyone who is pulled over by an unmarked vehicle to call 911 for verification that it is a legitimate law enforcement stop.