Results indicate that Japan maintains near-perfect homicide clearance rates of around 95 percent, compared with roughly 60 percent in the United States. Several incident-level characteristics which increase the likelihood of homicide clearance were more common in Japanese than in American homicides. Most obvious was Japan’s much higher proportion of homicides committed with weapons other than firearms; cases involving a firearm weapon are less likely to clear than those involving a knife or strangulation as the lack of close contact with the victim means that less physical evidence is found. Japan also had a much higher proportion of family homicides than the United States; homicides committed by offenders known to the victim had a greater chance of clearance than those perpetrated by a stranger. Japan had a higher proportion of homicides of children younger than 13 than the United States; homicide incidents with child victims were found to have a greater chance of clearance. Hard to clear homicides with teenage or young adult victims were less common in Japan than in the United States. The Japanese categorization of homicide in official statistics, which excludes robbery-homicide and includes attempted homicide, was determined to be somewhat favorable for producing high clearance rates in Japanese official homicide statistics. Japan’s higher homicide clearance rates might therefore lead to a conclusion that Japanese police are more effective that their American counterparts. However, factors unrelated to police effectiveness, such as clearance-friendly incident characteristics, and the categorization of homicides in official statistics play some part in producing Japan’s high homicide clearance rates. Clearance rates should not be used exclusively to compare police effectiveness and performance, or police-citizen cooperation in the two countries. Figures, notes, references