Elder mistreatment is complex, with cases typically requiring integrated responses from social services, medicine, civil law, and criminal justice. Only limited research exists describing elder mistreatment prosecution and its impact. Researchers have not yet examined administrative prosecutorial data to explore mistreatment response, and no standardized analytic approach exists. We developed a rigorous, systematic methodologic approach to identify elder mistreatment cases in prosecutorial data from cases of crimes against victims aged ≥60. To do so, we operationalized elements of the accepted definition of elder mistreatment, including expectation of trust and vulnerability. We also designed an approach to categorize elder mistreatment cases, using the types of charges filed, into: financial exploitation, physical abuse, sexual abuse, verbal/emotional/psychological abuse, and neglect. This standardized methodological approach to identify and categorize elder mistreatment cases in prosecution data is an important preliminary step in analyzing this potentially untapped source of useful information about mistreatment response.