Law enforcement’s use of facial recognition technology during investigations has blossomed in recent years thanks in no small part to a booming surveillance industry built on the back of an ever-expanding buffet of publicly available biometric data. The limits on where and how that technology can be used though remain legally murky and are constantly evolving. Now, it appears at least some law enforcement agents are flirting with the idea of using facial recognition at otherwise seemingly benign traffic stops, a potential loosening of the tech’s use that has legal and privacy experts on edge.
As first reported earlier this month by Insider’s Caroline Haskins, that hypothetical was floated during a 2021 episode of the Street Cop Training podcast, a program intended for police officers looking to learn new investigative techniques. In the episode, the show’s host, Dennis Benigno poses a scenario to his guest, Nick Jerman.
“Let’s say you are on a traffic stop and we have someone in the car who we suspect may be wanted?” Benigno asked. “How would you go about investigating somebody who you think may be trying to hide their apprehension and hide out who they are?”
Jerman, who had spent the rest of the episode describing ways to use publicly available social media tools to identify potential targets during a police investigation, responded by saying, “there are a couple paid programs you can use, [presumably referring to Clearview AI and apps like it] where you can take their [the driver’s] picture and it will put it [the photo] in.”
In other words, if a police officer feels uncertain of a driver, or possibly even a passenger’s identity, they could quickly snap a photo of their face and feed it into a facial recognition database to gather more information.
Though said in passing, the situation laid out by Jerman could represent a radical shift in the ease and frequency with which police use facial recognition, a technology many privacy advocates warn lacks sufficient accuracy, particularly when identifying people of color.
The situation may also violate U.S. laws.
Gizmodo spoke to Nate Wessler, the Deputy Director of the American Civil Liberties Union’s Speech, Privacy, and Technology Project, who pointed to a growing patchwork of cities and states all around the country that have passed local legislation limiting public facial recognition use. In many of those cases, from San Francisco to Portland, this type of brazen, fire from the hip style use of the technology would likely violate local laws. Wessler said that traffic stop facial recognition could also potentially violate laws of states like Maine where law enforcement are allowed to use facial recognition but only for serious felonies and with a warrant.
Speaking more broadly, Wessler said error rates inherent in the technology, while improving, are still too high for any match to act as probable cause to arrest someone.
“These are probabilistic algorithms that are making their best guess based on the quality of the photo that’s uploaded and what’s in the database and how the algorithm was trained,” Wessler said. It should be noted Gizmodo was not able to independently confirm any cases of this technique being used by law enforcement in any known arrests, so far.
Images collected by police at traffic stops, likely captured in haste using a smartphone under imperfect conditions, would also be unlikely to replicate the same levels of accuracy seen in more recent, high-profile facial recognition tests. “So if you had police pull someone over and use face recognition technology, and then it spits out a purported match to somebody who they think has an outstanding warrant and then they arrest that person on the spot just based on that face recognition result that would not be probable cause to arrest,” Wessler added.
In that situation, Wessler warned police using facial recognition at a traffic stop could open themselves up to a false arrest lawsuit under the Fourth Amendment. Still, Wessler said case law around law enforcement use of facial recognition remains relatively sparse due to the newness of the technology.
Greg Nojeim, a Senior Counsel and Co-Director of the Security and Surveillance Project at the Center for Democracy & Technology told Insider he be believed Jerman’s recommendation to use facial recognition at a traffic stop would cross the line into illegality if the police didn’t have “reasonable suspicion” if the targeted individual had committed a crime. Reasonable suspicion though is a notoriously fraught term and can vary widely in its interpretation.
The New York Police Department, for its part, claims matching photos from a facial recognition search aren’t enough on their own to justify an arrest but instead should serve as a “lead” for further investigation.
“The detective assigned to the case must establish, with other corroborating evidence, that the suspect identified by the photo match is the perpetrator in the alleged crime,” the NYPD states. Yet, in other cases, faulty facial recognition matches have reportedly led to false arrests. In one of the most notable cases, a 43-year-old year father named Robert Williams was forced to spend 18 hours behind bars without being told why after Detroit police arrested him based on a faulty facial recognition match.
If you do happen to find yourself in the undesirable position of having a police officer shove a smartphone camera in your face, there are several things you can do. Wessler said drivers caught in that situation have the right to verbally tell an officer that they do not consent to have their biometrics (in this case, their face scan) collected. That might not mean shit to an officer at the moment, but Wessler said it could help down the line for people trying to litigate over their rights. People also have the legal right to record a police officer with their own phone which, in some cases, could deter police from crossing the line into scanning your face.
All that said, if recent cultural touchstones are any reminder, even the most basic traffic stops in the U.S. have the potential of rapidly escalating from routine to potentially deadly in just seconds. With that nightmare in mind, Wessler said people need to make their own decision about what actions or responses feel safe at the time.
On a more practical level, Wessler said it’s unclear what real policing advantage law enforcement hopes to gain by using facial recognition at a traffic stop. In that situation, police already have the authority to ask a driver for their driver’s license, which they can then run against their own databases. The privacy tradeoff, in other words, just isn’t worth it.
“This seems unnecessary,” Wessler said, “It’s putting this incredibly powerful and unregulated surveillance tool in the hands of beat cops to use with no oversight, no rules, no predicate level of suspicion, no confirmatory steps. And that’s just a recipe for disaster.”