Presents findings, for a five-year period from 2006 to 2010, on the characteristics of crime victimizations that went unreported to police, according to data from the National Crime Victimization Survey. The characteristics examined in this report include the type of crime, whether it involved a weapon or injury, the victim-offender relationship, and demographic characteristics of the victim. For each of the characteristics examined, the report also details victims' rationale for not reporting to the police, including beliefs that the police would not or could not help, that the crime was not important enough to report, or fear of reprisal or getting the offender into trouble. The report also examines trends from 1994 to 2010 in the types of crime not reported to the police and the reasons victimizations went unreported.

• From 1994 to 2010, the percentage of serious violent crime-rape or sexual assault, robbery, or aggravated assault-that was not reported to police declined from 50% to 42%.
• From 2006 to 2010, the highest percentages of unreported crime were among household theft (67%) and rape or sexual assault (65%) victimizations, while the lowest percentage was among motor vehicle theft (17%) victimizations.
• From 2006 to 2010, a greater percentage of victimizations perpetrated by someone the victim knew well (62%) went unreported to police, compared to victimizations committed by a stranger (51%).