In this article series, we’ve taken a look at three data-intensive technologies that are giving law enforcement agencies unprecedented access to mission-critical information in the field, at the station, in the crime lab and in the real-time crime center. Added to the list — along with body-worn cameras, drones and automated license plate readers — is a lesser-used but powerful technology that has shown the potential to quickly help narrow investigative leads, locate suspects as well as missing persons and verify identities in controlled settings like correctional facilities and border crossings: facial recognition. From image comparison to investigative intelligence At its simplest, facial recognition technology compares an image of a face against a database of known images and returns possible candidates. That process can support a range of legitimate public safety needs, from verifying the identity of an unknown person to helping identify a suspect in a serious violent crime. The most useful way to understand facial recognition is as a tool for narrowing investigative leads. It does not replace an investigator, establish probable cause by itself or eliminate the need for corroborating evidence. Rather, it can help trained personnel quickly sort through a mountain of images and focus their next steps. Investigators working a violent assault may have a partial image from a security camera. A facial recognition search may return several possible candidates for review. From there, investigators still need to compare the result with other evidence, such as witness statements, location data, records checks, vehicle information or additional video. In the case of a missing person, a possible match may help investigators identify a person seen on camera at a transit station, hospital or public venue. In unidentified remains cases, facial comparison may be one piece of a broader forensic effort that also includes fingerprints, dental records,