Read the passage: 'Before towing a vehicle, the trooper must attempt to contact the registered owner and document the attempt. If the owner cannot be reached, the vehicle may be towed and an inventory completed.' What must happen before a vehicle is towed?

1. The vehicle must be sold at auction
2. The trooper must attempt to contact the registered owner and document the attempt
3. The vehicle must be searched for weapons only
4. A supervisor must personally arrive at the scene