Civil liberties advocates have also raised issues with the lack of public engagement
The Chicago Transit Authority (CTA) is set to expand its artificial intelligence-based gun detection programme across more of its train platforms, despite mounting concerns from civil liberties groups about its transparency and effectiveness. The move follows the CTA board’s recent approval of a USD 1.2 million contract with surveillance technology company ZeroEyes, significantly scaling up an ongoing pilot that began last summer.
Under the expanded plan, ZeroEyes’ gun detection software will be deployed across 1,500 cameras by mid-2026, a sharp rise from the current 250 cameras currently used on L station platforms. This expansion follows an initial USD 200,000 pilot project, which, according to CTA officials, has identified 10 actual firearms out of 82 total detections and led to six arrests.
Acting CTA President Nora Leerhsen said the programme was a “proactive” use of the transit system’s 33,000-camera surveillance network. “This is a proactive use of those cameras,” Leerhsen told board members, highlighting that many of the cameras offer high-definition video feeds that can be analysed by ZeroEyes’ software to detect visible firearms.
Kevin Ryan, CTA’s Vice President of Security, defended the programme, stating that ZeroEyes alerts police only after a human analyst at the company verifies the detection. He said this process prevents law enforcement from being notified in approximately 98 per cent of cases, such as when an object is clearly a toy like a Nerf gun. Of the 10 confirmed gun detections, six led to arrests, including one suspect linked to two robberies targeting CTA passengers.
Still, concerns about the programme’s reach and transparency persist. The AI system only monitors cameras on station platforms and is designed to detect weapons that are openly visible. It did not, for instance, flag a quadruple shooting that occurred aboard a Blue Line train last September—an incident that some critics say underscores the system’s limitations.
Civil liberties advocates have also raised issues with the lack of public engagement. Ed Yohnka, a spokesperson for the American Civil Liberties Union (ACLU) of Illinois, questioned the repeated reliance on surveillance solutions without community input or clear evidence of improved safety.
“For more than two decades, riders on CTA buses and trains have been promised that the next surveillance camera system … or some other surveillance technology will make all feel safer and more confident on the trains,” Yohnka said. “How much more secure could CTA trains and buses be if, rather than expend millions of dollars on technology, the money would have been invested in measures that actually improve safety? This is simply another missed opportunity.”
While CTA officials have justified the expansion on the grounds of enhancing security, they have not disclosed which stations or specific cameras will use the upgraded software. Ryan told the board that deployment decisions would be guided by historical crime data to ensure the most effective coverage.
As the CTA moves ahead with expanding AI-powered surveillance, the debate between public safety and civil liberty is likely to intensify—particularly around issues of accountability, data privacy, and the role of technology in policing public spaces.
