Manassas City police have released a sketch of a man who may have left threatening notes at the front doors of residences.

Since the beginning of December, there have been about 20 incidents in which threatening notes were left and/or a suspicious person was seen. Three of the most recent notes were left in or near the Sumner Lake neighborhood on March 2 and March 4, police said.

The man in the sketch is described as being of average height and having light-brown to black hair, a light to medium complexion and a medium build.

Anyone with information can call Crime Solvers at 703-330-0330. Calls are confidential.