There's an action movie cliché in which a cop inspects the body of a felled assassin or foot soldier and discovers a curious tattoo that ultimately leads to a rogue black-ops squadron, a secret religious sect, or an underground drug trafficking ring. 

The trope isn’t entirely Hollywood fantasy, but the reality of emerging tattoo recognition technology is closer to a dystopian tech thriller. Soon, we may see police departments using algorithms to scrape tattoos from surveillance video or cops in the field using mobile apps to analyze tattoos during stops. Depending on the tattoo, such technology could be used to instantly reveal personal information, such as your religious beliefs or political affiliations.

This report was co-written by MuckRock Editor JPat Brown. MuckRock Co-founder Michael Morisy, MuckRock Intern Lukas Knight, and EFF Activism Intern Annelyse Gelman also contributed to this report. Another version appears at MuckRock.com.

Law enforcement agencies around the country are increasingly embracing biometric technology, which uses intrinsic physical or behavioral characteristics—such as fingerprints, facial features, irises, tattoos, or DNA—to identify people, sometimes even instantly. Just as the technology that powers your cell phone has shrunk both in size and cost, mobile biometric technologies are now being deployed more widely and cheaply than ever before—and with less oversight.