A vehicle security system is provided for a vehicle having a braking system that includes a parking brake, the parking brake being capable of being switched between a driving position and a braking position. The vehicle security system is configured to secure the vehicle after an accident. The vehicle security system comprises a control unit configured to ascertain an accident of the vehicle and to switch the parking brake of the vehicle into the braking position in response to ascertaining an accident of the vehicle, and a sensor configured to capture and make available first vehicle data that represent a rotary location of the vehicle. The control unit is configured to carry out the ascertainment of an accident on the basis of the first vehicle data.