A physician approach to accident investigation is described. Exterior and interior damage must be systematically noted, quantitated and recorded. Photography is a useful tool for recording vehicle damage which is transient because accident vehicles are quickly repaired or destroyed. Correlation of exterior and interior vehicle damage and occupant injuries usually make it possible to determine vehicle and occupant kinematics. Determination of the Collision Deformation Classification and the impact speed (delta v) is done by analysis of investigation data.