A man facing murder charges for a fatal stabbing on a Chicago train reportedly captured the incident and its aftermath on his cellphone, prosecutors have revealed.

According to FOX 32 Chicago, Demetrius Thurman, 40, stands accused of murdering 37-year-old Dominique Pollion. The tragic event unfolded early Saturday morning when Pollion was asleep on a Blue Line train.

Records reviewed indicate Pollion had been resting in the train car for nearly an hour before the incident, with no prior interaction between him and Thurman, who were strangers to each other, according to prosecutors.

Allegedly, Thurman approached Pollion from behind at approximately 2:17 a.m., began recording with his phone, and stabbed him with a knife that featured a bright-orange handle. The attack involved a stab wound to the chest near Pollion’s heart and another to his abdomen, court documents reveal.

Prosecutors assert that Thurman not only recorded the lethal attack on his phone but was also identified as a suspect with the aid of CTA surveillance footage.

After being attacked, Pollion awoke in distress, screaming and attempting to escape by moving down the train car aisle before ultimately collapsing, according to prosecutors. Following the assault, Thurman reportedly transferred to another train.

Pollion was taken to a nearby hospital, where he later died.

CTA surveillance video captured the attack and its aftermath, prosecutors said, as did video recorded on Thurman’s phone.

A security officer talks with a passenger on a Blue Line train at the CTA Forest Park station in Chicago. (John J. Kim/Chicago Tribune/Tribune News Service via Getty Images)

Immediately after the stabbing, court documents say, Thurman pointed the phone toward himself, capturing his face on video.

When the train arrived at the Clark/Lake station a short time later, a passenger alerted security officers on the platform. While outside the train car, Thurman allegedly turned the camera on himself again and said, “somebody got his ass,” before leaving the station.

Investigators gathered images from surveillance video that prosecutors said showed Thurman’s face and submitted them to Illinois’ facial recognition program, which led to his identification.

Investigators allege that a Chicago man recorded a fatal Blue Line train stabbing and its aftermath on his phone, with CTA video helping identify the suspect. (Terrence Antonio James/Chicago Tribune/Tribune News Service via Getty Images)

Police later issued a bulletin, and a Chicago police officer who had encountered Thurman just days earlier recognized him. The officer said Thurman had been sleeping on a Blue Line train at the time and provided his driver’s license during that encounter.

Thurman was arrested Sunday. Court documents say he was wearing the same clothes seen in the surveillance video and was in possession of a cellphone that contained recordings of the stabbing, along with photos of other passengers sleeping on the train.

Prosecutors said Thurman’s cousin also identified him as the person seen on surveillance video, and they allege Thurman admitted to stabbing Pollion. He was charged with first-degree murder.

FOX 32 reported that Thurman’s criminal past includes disorderly conduct, DUI and a 2023 traffic arrest. His next court date is scheduled for Jan. 20.

Crime on the CTA drew federal scrutiny after a November incident in which a man set a woman on fire aboard a downtown train.

On Dec. 19, federal transit officials ordered the agency to submit a tougher safety plan within 90 days or risk losing a quarter of its federal operating funds.