The FBI is piloting Amazon’s facial matching software—Amazon Rekognition—as a means to sift through mountains of video surveillance footage the agency routinely collects during investigations.

The pilot kicked off in early 2018 following a string of high-profile counterterrorism investigations that tested the limits of the FBI’s technological capabilities, according to FBI officials.

For example, in the 2017 mass shooting in Las Vegas carried out by Stephen Paddock, the law enforcement agency collected a petabyte worth of data, much of it video from cellphones and surveillance cameras.

“We had agents and analysts, eight per shift, working 24/7 for three weeks going through the video footage of everywhere Stephen Paddock was the month leading up to him coming and doing the shooting,” said FBI Deputy Assistant Director for Counterterrorism Christine Halvorsen.

Halvorsen made those remarks in November at the Amazon Web Services re:Invent conference in Las Vegas, where she described how the FBI is using Amazon’s cloud platforms to carry out counterterrorism investigations. She said Amazon Rekognition could have gone through the same trove of data from the Las Vegas shooting “in 24 hours”—or three weeks faster than it took human FBI agents to find every instance of Paddock’s face in the mountain of video.

“Think about that,” Halvorsen said, noting that technology like Amazon Rekognition frees up FBI agents and analysts to apply their skills to other aspects of the investigation or other cases.

“The cases don’t stop, the threats keep going,” Halvorsen added. “Being able to not pull people off that and have computers do it is very important.”

While Amazon is now a significant supplier of technology to the government—much of it through its cloud business, AWS, which includes the CIA and Defense Department as customers—it is less clear how its facial recognition software is being used in the public sector. The Daily Beast reported the company pitched the software to Immigration and Customs Enforcement officials last summer, a move that has lawmakers and Amazon employees asking questions. The company does not list any federal clients on its customer page, and currently only identifies as a customer one local law enforcement agency, the Washington County Sheriff Office. According to press reports, the city of Orlando recently began a second pilot of Amazon's Rekognition software.

The FBI did not respond to questions about its use of Amazon Rekognition from Nextgov.