To address the concern of suffocation, a semipermeable air bag was suggested. Bench scale tests were performed to demonstrate the validity of that suggestion. Simple leaf blowers were used for the bench scale tests, and although they served those tests adequately, they were determined to be underpowered for the final design. A full-car-width air bag was also tested to evaluate the volume in the back seat having to be filled, as well as deployment from the ceiling. Information gained from these tests was used for the prototype design. The objective of this system is to use an air bag to prevent an individual, or individuals, from continuing violent actions while being transported in a patrol vehicle without requiring immediate physical contact by the law enforcement officer. The air bag independently restricts the amount of physical activity occurring in the rear seat of the vehicle while allowing the officer to stop the vehicle safely. The air bag can also provide the officer additional time to get backup personnel to aid him/her if the situation warrants it. 7 figures