All states have enacted mandatory or preferred arrest statutes that require or encourage officers to arrest the batterer in domestic violence incidents when probable cause exists. Mandatory arrest laws still allow officers much choice about when to arrest, because the criteria for whether there is enough evidence to meet the standard of probable cause are ambiguous. Officers use several legal and extralegal criteria to make arrest decisions and also rely on stereotypes to form inferences about specific cases. This entry describes findings from numerous studies that have examined how officers interpret, investigate, and respond to domestic violence situations. A focus on how officers infer and interpret information is important to design effective academy training that addresses the unintentional effects of stereotypes and improves police decision ...