These tests indicate, first, that the majority of incidents are initiated by officers themselves, rather than by citizens. Second, it is probable that black officers are victimized at a higher rate than white officers, especially while off-duty and by black assailants. Third, the modal type of precipitating incident is 'attempting other arrests (general)', and not, as commonly thought, domestic disputes. Implications of these findings are then discussed. Thirty-five references are provided. (Author abstract modified)