Janesville police are investigating a number of thefts from automobiles over the last couple of nights. About a dozen incidents have been reported. The first set of thefts Tuesday night, in what's known as the Look West Neighborhood, resulted in the arrest of a 19-year-old Janesville man. Police say they were able to track him by his footprints in the fresh snow. Police believe whoever is responsible for the thefts Wednesday night, in the area of Saint Mary's School, were using a vehicle. Police say part of the problem is people are leaving their vehicles unlocked.