Damone Williams-Tillman was arrested Saturday on suspicion of killing Josselyn Bishop, 19, a Mankato State University student.
Bishop, a native of Henderson, had been the victim of multiple stab wounds. Her body was found by a roadside in Mankato on Friday afternoon.
Williams-Tillman, also 19, lives in Golden Valley. He was booked into Blue Earth County Jail, where he's being held with a pending charge of second-degree murder.
Mankato police believe Williams-Tillman was seen driving his blue Ford Focus in the area that Bishop's body was recovered, and are attempting to recover any surveillance video that might put Williams-Tillman or his car at the scene.
Police believe Williams-Tillman and Bishop had a previous relationship, but wouldn't speculate on the nature of it.