Abstract
Crime statistics provide a measure of offenses against society. The set of offenses that are counted as crimes vary across time and jurisdictions, but standardized definitions promote consistency of measurement. Sources of crime data include court records, law enforcement agencies, surveys asking respondents about their experiences as victims or offenders, vital statistics programs, and emerging data sources such as social media and crowdsourcing. Each data source has its strengths and limitations, and a more complete picture of crime can be obtained by examining multiple sources. Major challenges include measuring crimes not currently captured by law enforcement agency statistics and surveys, and improving data quality.