The analysis was based on life tables generated for each year's cohort of new handguns to estimate gun-years at risk, analogous to person-years, for rate and relative risk calculation. Of 735 firearm homicides of police officers during the study period, 435 were committed with 428 civilian-owned handguns. Revolvers were used more often than pistols. For both types of handgun, .22-caliber weapons were least often used in police homicides, while .32-caliber pistols and .38-caliber revolvers were used most often. Forty-six percent of the handguns included in this sample had a barrel length of three inches or less. U.S. firearms manufacturers produced 82 percent of the handguns for which a manufacturer could be identified at all. 1 figure, 1 table, and 24 references