The U.S. Secret Service (USSS) has begun field testing a mobile facial recognition application called “Sentry” that could be at odds with a 2024 Privacy Impact Assessment (PIA).
No separate PIA for Sentry has been made public.
The nearly two-year-old PIA says the Secret Service Office of Investigations (since renamed the Office of Field Operations), “does not use facial recognition technology to surveil the public.”
The PIA also states that the Secret Service does not use commercially provided services and “does not have the capability and will not procure any device” to analyze live video, streaming media, or other media in real time.
Sentry is being tested by 25 Secret Service Uniformed Division officers in Washington, D.C. to determine whether the technology should be deployed more broadly.
While the Uniformed Division is field testing Sentry, any operational deployment of the app would intersect with the Office of Field Operations, whose investigative and field office agents use biometric tools, including facial recognition, to help identify individuals, develop investigative leads, and support threat assessment and protective intelligence work.
The app allows the officers to scan a person’s face or fingerprints with a smartphone and compare the images against government databases, marking the latest expansion of federal biometric identification tools into street-level federal law enforcement encounters.
The Secret Service’s interest in facial recognition predates Sentry. In 2018, the agency conducted a Facial Recognition Pilot (FRP) at the White House Complex to test whether the technology could help identify “known subjects of interest” before officers or agents made direct contact with them.
That earlier pilot used video streams from selected cameras in the Secret Service’s existing Crown CCTV system. The cameras captured people on sidewalks and streets around the White House, including one open public area and one controlled area.
The system was designed to detect faces in those video streams and compare them against a small gallery of volunteer Secret Service employees.
The 2018 PIA for the pilot shows the operational concept behind Sentry was already in place using biometric comparison to give Secret Service personnel an identity lead before an encounter.
The 2018 PIA also anticipated future expansion. It said the Secret Service could update the assessment for later field tests and could use facial recognition at other White House locations or additional protected sites. No new PIA specifically for Sentry though has been made available.
Sentry appears to move the same basic idea into the field by putting biometric scanning on officers’ phones.
The American Civil Liberties Union (ACLU) warned at the time that even a limited pilot on White House grounds opened the door to broader public space facial recognition around areas where demonstrations, tourism, and ordinary public activity occur.
In July 2019, Joseph Di Pietro, then the USSS’s chief technology officer in the Office of Technical Development and Mission Support, told Congress “the Secret Service is evaluating the potential benefits of [facial recognition] technology to this agency’s protective mission.”
“Applied correctly and with appropriate controls,” Di Pietro said, “this technology could potentially be used by the Secret Service to enhance our security posture at critical protective venues, Specifically this technology may have the potential to provide an early notification to Secret Service personnel of individuals who are of record with the agency when they approach a protective site.”
Di Pietro added that “while the FRP started in December 2018 … the Secret Service began contemplating this pilot in August 2014.”
In a 2021 report, the Government Accountability Office (GAO) said that “as of March 31, 2020, the Facial Recognition Pilot system was not in operation and no longer undergoing testing by the Secret Service.
GAO said USSS “officials told us that after six months of data collection and subsequent data analysis, they decided not to use the system in its operations and deleted all stored data and photos.”
Clearly, though, the agency continued its evaluation of expanding its use of facial recognition. Biometric Update reported that in September 2024, the Secret Service had issued a PIA titled, “USSS Use of Facial Recognition Technology, that supposedly covers the agency’s use of facial recognition technology for law enforcement and criminal investigative purposes.
The PIA says Secret Service Office of Investigations personnel may use photos or still frames from video as “probe images” to search government facial recognition systems to develop investigative leads, and that the technology is limited to authorized investigations, including counterfeiting, financial and cyber-enabled crimes, and that results must be treated as leads requiring human review, corroboration and further investigation before action.
The PIA also says the Secret Service does not use facial recognition to surveil the public, does not use commercial facial recognition services, and will not procure real-time video analysis capability.
The unresolved question then is whether the Department of Homeland Security (DHS) – which the Secret Service is part of – views Sentry as covered by existing Secret Service facial recognition privacy documents, or whether its mobile, field-based use by uniformed protective officers requires a separate or updated privacy assessment, which so far has not been made public if it exists.
According to what is known, the Sentry pilot is limited for now, but the technology is significant because it places biometric identity checks in the hands of officers who protect federal buildings, foreign embassies, and the White House complex.
Unlike the plainclothes agents most closely associated with presidential protection, the uniformed division officers testing the app are part of the visible USSS police force that secures fixed sites in the nation’s capital.
Sentry reportedly works by allowing an officer to use a phone camera to scan a person’s face or fingerprints. The app then compares the images to large government databases and returns possible identity information.
The way the system has been described, it is suspiciously similar to Mobile Fortify, the facial recognition and biometric app used by Immigration and Customs Enforcement (ICE) and Customs and Border Protection (CBP) during field encounters.
Sentry was built on the same technical infrastructure as Mobile Fortify, much of it belonging to CBP, and uses many of the same databases, according to officials cited by Bloomberg.
The Secret Service version also draws on the Department of State’s passport photo database, among other biometric and law enforcement databases.
The vendor behind Sentry has not been publicly identified. However, DHS’s 2025 AI Use Case Inventory identified NEC as the third-party vendor whose technology supports CBP’s Mobile Fortify biometric matching capability.
That does not prove NEC is the prime contractor for Sentry, and no public document reviewed so far appears to identify the Secret Service app’s vendor. Sentry does share the same infrastructure as Mobile Fortify.
The Secret Service says the app will not be used to scan crowds indiscriminately. According to agency officials cited in reporting, Sentry is intended to scan a specific person, ot everyone in a public area.
Officers are mostly required to seek a person’s consent before using the app, staff must complete training before using it, and the tool is supposed to be used alongside other sources of information rather than as a stand-alone decision system.
The Secret Service said photos and data collected through Sentry will not feed back into the databases queried by ICE agents using their version of the technology.
Those assurances may limit the immediate scope of the pilot, but they leave important questions unanswered.
The public record so far does not identify the app’s vendor, the precise databases queried, the legal threshold for use, the match threshold, the retention schedule for scanned images, the rules for U.S. citizens, the appeals process for misidentification, or whether a dedicated privacy impact assessment has been completed for Sentry.
Those gaps matter because Mobile Fortify has already become one of the most controversial biometric tools in federal law enforcement.
Civil liberties organizations have criticized ICE’s use of Mobile Fortify as invasive, error-prone, and inadequately governed. The Electronic Frontier Foundation and other groups have called for DHS to shut down Mobile Fortify, release its privacy analyses, and clarify its facial recognition policies.
DHS’s AI inventory describes Mobile Fortify as a deployed, high-impact computer vision law enforcement system. The inventory says ICE’s impact assessment, independent review, monitoring protocols, operator training protocols, fail-safe process, appeals process, and end-user feedback process were still in progress.
That means a related system was already being used in the field while key oversight components were not yet complete.
For the Secret Service, the rationale for Sentry is protective intelligence. The agency is responsible for preventing attacks on the president, vice president, visiting foreign leaders, major candidates, and protected sites.
But for privacy and civil liberties advocates, the danger is mission creep. A tool introduced for a narrow protective purpose can become normalized, expanded, and shared across agencies.
Mobile Fortify began as an immigration enforcement tool but now provides the model and infrastructure for a Secret Service protective policing app. The same architecture that checks identity at the border or during immigration operations can be repurposed for encounters near embassies, federal buildings, protests, and public events.
Nathan Freed Wessler, deputy director of the ACLU’s Speech, Privacy, and Technology Project, told Bloomberg he was concerned that such systems could spread further among federal, state, and local law enforcement agencies.
Wessler described the power as one that could help create a “checkpoint society.”
For now, Sentry appears to just be a pilot involving a couple dozen uniformed officers in Washington, D.C. But its importance is larger than the pilot’s size. It shows that mobile biometric identification is moving beyond immigration enforcement and border management into the protective security mission of the Secret Service.
And that makes Sentry not just another app, but another sign of how federal law enforcement is turning the face into a field-searchable credential.
Article Topics
biometric matching | biometrics | facial recognition | law enforcement | mobile app | Secret Service | Sentry | U.S. Government