Under California Vehicle Code § 27315 (Mandatory Seatbelt Law), failure to wear a safety belt does not automatically bar an injured party from recovering damages. To reduce compensation under the **Seatbelt Defense**, the defendant carries the heavy burden of proving that seatbelt non-use directly caused or exacerbated specific injuries.
1. Defendant's Three-Part Burden of Proof
In *Franklin v. Gibson*, the California Court of Appeal ruled that defendants must establish through expert biomechanical testimony: (1) an operational safety belt was available, (2) a reasonably prudent person would have used it, and (3) what specific injuries would have been avoided had the restraint been fastened.