Vermont State Police believe a missing woman whose 2-year-old son was found alone in her SUV with the engine running is a victim of foul play.

Thirty-three-year-old Melissa Jenkins of St. Johnsbury has been missing since Sunday night. A friend who was looking for her called police. Authorities say it appears from the scene that there was a struggle.

The SUV was not far from Jenkins' home. A relative believes she was trying to help someone at the time.

The Vermont Air National Guard is searching for Jenkins by helicopter, and police are using search dogs.

Jenkins is a single parent who teaches science and coaches girls basketball at St. Johnsbury Academy. She is also a part-time waitress at The Creamery Restaurant in Danville.