Family of man stabbed to death on CTA sues transit agency, private security companies

The family of a man who was stabbed to death on a CTA Blue Line train in January is now suing the transit agency and the private security firms working at the time.

On Jan. 10, 2026, investigators say Demetrius Thurman stabbed 37-year-old Dominique Pollion near the Clark/Lake station while he was sleeping on the train. Thurman, 40, used his phone to record video of the crime, according to prosecutors.

Prosecutors said Pollion had been asleep on the train for about an hour when Thurman got on the same car around 2:15 a.m., with a phone in one hand and a knife in the other. Prosecutors said Thurman approached Pollion from behind and started recording the video on his phone before stabbing Pollion in his chest and stomach.

The attack woke Pollion up, who screamed and backed away from Thurman, who followed him and put his camera on selfie mode before Pollion collapsed.

When the train stopped at Clark/Lake another passenger alerted the security officers on the platform about the stabbing, who then found Pollion inside the train. The officers couldn't immediately tell he'd been stabbed because of how many layers of clothing he was wearing, prosecutors said. He was taken to Northwestern Memorial Hospital where he was pronounced dead.

Pollion's family is now suing CTA and security firms Monterrey Security Consultants, Inc., and Action K-9 Security, Inc., for reckless disregard for patron safety.

The lawyers representing the family are expected to hold a news conference about this suit later Tuesday afternoon.