ACLU Reports Police Use AI and ALPR Data to Flag Drivers for 'Suspicious' Travel

AI-Driven Traffic Stops on the Rise

Law enforcement agencies are increasingly employing artificial intelligence (AI) algorithms and automated license plate reader (ALPR) surveillance data to identify motorists whose travel histories are deemed "suspicious." This practice, highlighted in an October 26 report by the American Civil Liberties Union (ACLU), allows police to initiate traffic stops even without initial evidence of a specific crime.

Jay Stanley, a senior policy analyst with the ACLU Speech, Privacy, and Technology Project, stated that this approach could lead to an increase in "pretextual stops." He expressed concern that these AI algorithms would inevitably flag more innocent individuals than actual wrongdoers, subjecting them to police encounters.

Concerns Over Mass Surveillance and Privacy

The ACLU's warning emphasizes privacy concerns related to mass surveillance. The use of ALPRs and AI-powered tools enables police to track the movements of individuals not suspected of any wrongdoing, potentially leading to unwarranted stops and questioning based solely on algorithmic assessments of travel patterns.

This development raises questions about the misuse of data and the potential for AI-generated alerts to serve as the primary justification for police interactions, rather than concrete evidence of criminal activity.

Case Example: Grace Knowles' Encounter

The ACLU's blog post opens with an account of Grace Knowles, a woman in her 20s from northern Virginia. In September 2025, during a road trip through Oregon, Texas, and Louisiana, she was pulled over in Florida by an officer who claimed she had spent too much time driving in the left lane.

The officer, who identified himself as a special agent with the Federal Bureau of Investigation (FBI) working on a human and drug trafficking project, informed Knowles that her license plate had been flagged for suspicious travel patterns. He questioned her about her travels and requested proof of her presence in New Orleans before she convinced him she was on a personal road trip.

Implications for Law Enforcement Practices

The reported increase in AI-derived pretext for traffic stops suggests a shift in law enforcement tactics. While ALPRs have traditionally aided in investigating existing crimes, their current application extends to proactively flagging drivers based on perceived "suspicious" behavior, as determined by AI.

This practice could broaden the scope of police discretion and potentially lead to more individuals being stopped and questioned without a clear, specific suspicion of criminal activity.