Amazon’s facial-recognition tech empowering the police
HILLSBORO, Oregon: When workers at an Ace Hardware here reported that a woman had walked out of the store with an US$11.99 tank of welding gas that she hadn’t paid for in her tote bag, an elaborate high-tech crime-fighting operation sprang into action.
A Washington County sheriff’s detective, working with the agency’s Special Investigations Unit, ran the store’s surveillance footage through an internal facial-recognition software built by Amazon, revealing a possible match.
That woman’s licence plate was flagged and, three months later, a narcotics officer in an unmarked SUV saw it and radioed other patrol deputies to stop her. A deputy clapped a pair of handcuffs around her wrists, an arrest report states. She said she’d needed the fuel to fix her car.
In late 2017, the Washington County Sheriff’s Office became the first law enforcement agency in the US known to use Amazon’s artificial-intelligence tool Rekognition, transforming this thicket of forests and suburbs into a public testing ground for a new wave of experimental police surveillance techniques.
Almost overnight, deputies saw their investigative powers supercharged, allowing them to scan for matches of a suspect’s face across more than 300,000 mug shots taken at the county jail since 2001. A grainy picture of someone’s face - captured by a security camera, a social media account or a deputy’s smartphone - can quickly become a link to their identity, including their name, family and address. More than 1,000 facial-recognition searches were logged last year, said deputies, who sometimes used the results to find a suspect’s Facebook page or visit their home.
It’s impossible to tell, though, just how accurate or effective the technology has been during its first 18 months of real-world tests. Deputies don’t have to note in arrest reports when a facialrecognition search was used, and the exact number of times it has resulted in an arrest is unclear. Sheriff’s officials said the software has led to dozens of arrests for theft, violence or other crimes, but a public-records request turned up nine case reports in which facial recognition was mentioned.
“Just like any of our investigative techniques, we don’t tell people how we catch them,” said Robert Rookhuyzen, a detective on the agency’s major crimes team who said he has run “several dozen” searches and found it helpful about 75 per cent of the time. “We want them to keep guessing.”
Sheriff’s officials say face scans don’t always mark the end of the investigation: Deputies must still establish probable cause or find evidence before charging a suspect with a crime. But the Sheriff’s Office sets its own rules for facial-recognition use and allows deputies to use the tool to identify bodies, unconscious suspects and people who refused to give their name.
The search tool’s imperfect results raise the risk of an innocent person being flagged and arrested, especially in cases of the scanned images being blurred, low-quality or partially concealed. Deputies are also allowed to run artist sketches through the search, an unusual use that AI experts said could more often lead to a false match.
Amazon’s guidelines for law enforcement say officials should use Rekognition’s results only when the system is 99 per cent confident in a match. But deputies here are not shown that search confidence measurement when they use the tool. Instead, they are given five possible matches for every search, even if the system’s certainty in a match is far lower.
After fielding questions from The Washington Post, Amazon added language to those guidelines, stating that officers should manually review all matches before detaining a suspect and that the search “shouldn’t be used as the sole determinant for taking action.”
Just like any of our investigative techniques, we don’t tell people how we catch them. — Robert Rookhuyzen, detective