Which of the following files provides information about gang members?

The Query Gang Member Capability (QGM) is specifically designed for law enforcement agencies to access information regarding gang members and gang-related activity. This tool allows users to query various databases to retrieve pertinent information about individuals identified as gang members, facilitating investigations and public safety measures.

The other options do not focus on gang-related information: Supervised Release pertains to individuals under certain supervisory conditions after serving sentences, Identity Theft deals with crimes involving the unauthorized use of someone else's personal information, and the NCIC Denied Transaction File records transactions that have been blocked or denied within the NCIC system, none of which provide gang member data. Therefore, the QGM file is the correct choice for accessing gang member information.