CTA testing artificial intelligence to detect guns at train stations, but ACLU is raising questions

Chicago is testing a mass surveillance tool to detect guns at CTA stations, even as debate rages around the effectiveness of another detection system used by the city, ShotSpotter.

The Chicago Transit Authority announced Thursday it is one month into a year-long pilot program with ZeroEyes, a company that uses artificial intelligence to identify guns in surveillance video and alert police.

The CTA says it has deployed the technology on about 250 cameras at L stations — but it won't say which stations, city security concerns.

CTA spokeswoman Maddie Kilgannon defended the new technology as adding more "eyes" to its already expansive surveillance network of more than 33,000 cameras — the largest of any transit agency in the nation.

In a statement, CTA President Dorval R. Carter, Jr. said "this added measure of protection provides additional peace of mind to everyone."

“Ensuring the safety and security of our riders and employees is our number one priority at the CTA, and this pilot allows us to explore how new technology may be able to support these efforts,” Carter said.

ACLU Illinois spokesman Ed Yohnka said the biggest concern of his organization is the lack of public input.

ZeroEyes' technology was implemented without public discussion, he said. And it adds another layer of technology to a surveillance network that has failed to improve public safety.

"This adds an additional level of surveillance without a corresponding public discussion or debate if that level of surveillance is wanted by residents of Chicago," Yohnka said.

These technologies "all come with allure of adding more safety, but they never seem to deliver on that promise."

There's also the question of the technology diverting police and security resources to false alarms, Yohnka said.

The CTA acknowledged the system cannot distinguish between real and toy guns. That's why each potential gun detection is reviewed by humans before officers are dispatched, Kilgannon said.

When the ZeroEyes system detects a potential gun on CTA's surveillance cameras, the image is first reviewed by an employee at ZeroEyes to determine if it's likely a legitimate detection, Kilgannon said.

If the detection passes that test, an alert is simultaneously sent to Chicago police, the CTA and the Office of Emergency Management and Communications, she said.

Those agencies then determine if the call is worth responding to, reviewing information that includes the surveillance video, a description of the type of gun and location.

The process is quicker than reviewing 911 calls and may be more reliable than depending on a phone call from a CTA bystander, Kilgannon said.

The system has already sent alerts for law enforcement officers carrying rifles at L stations, she said. The system is designed only to detect guns in public view, Kilgannon said.

A CTA demonstration video shows the ZeroEyes system being tested on a man holding a rifle, then a pistol on the platform of the Blue Line's Illinois Medical District station.

CTA and CPD would not share the number of gun arrests attributable to ZeroEyes in its first month of operation. But the CPD did share that there have been 626 reports of violent crime on the CTA this year through Aug. 27, compared with 547 during the same period in 2023.

The CTA said it is paying $200,000 through a contract with ZeroEyes for a 12-month period. Those funds came from the CTA's $65.2 million 2024 security budget.

ZeroEyes has apparently been trying to curry business with the city for years. Kieran Carroll, the company's chief strategy officer, registered as a lobbyist from August 2022 until February 2023, although city records show he had no lobbying activity, compensation or expenditures over that period.

Since 2020, ZeroEyes has spent at least $845,000 on lobbying, according to OpenSecrets, a nonprofit that publishes data on campaign finance and lobbying.

While the company touts its existing deals with other transit agencies, schools and even Navy Pier, the technology has faced resistance from some lawmakers.

The governors of Missouri and Kansas — a Republican and Democrat, respectively — have both vetoed funding for programs supported by ZeroEyes, according to the Associated Press.

There’s scant research on the efficacy of gun-detection technology like the system deployed across the CTA.

A report published in January 2023 by the U.S. Department of Homeland Security showed that in a trial run, a group of first responders found ZeroEyes’ DeepZero software to be “intuitive.”

Perhaps most notably, they reported the technology could help spot a gun “within seconds of the object appearing on the screen.”

There also were downsides. The software had trouble detecting multiple people wielding weapons simultaneously, and lower-quality cameras made it difficult to clearly see an image.

“As a result, some evaluators questioned the utility of DeepZero in emergency response operations,” according to the report. Evaluators “ discussed that DeepZero might not prevent a mass shooting, but its faster notification to the facility and responders may reduce the number of casualties.”

Mayor Brandon Johnson campaigned on a promise to do away with ShotSpotter, a controversial gunshot-detection system that’s also powered by artificial intelligence. Since Johnson made good on that vow earlier this year, he has said his decision was informed by research.

Asked for research that showed ZeroEyes is effective, the CTA in an email said it would use the pilot "to assess how effective this tool may be for our system."

The CTA also declined to say how it determined which stations received the ZeroEyes technology, or how involved CPD was in the process. "Camera placement was a strategic security decision, and we do not provide comment on that strategy," the CTA said in an email.

A spokesperson for the mayor didn’t respond to questions about the CTA’s implementation of ZeroEyes.