The man suspected of lighting a sleeping woman on fire and then watching her die Sunday inside the New York City subway was arrested by police hours after the attack.

According to authorities, the assailant killed someone who was a stranger to him.

New York Police Department Commissioner Jessica Tisch said a person of interest was taken into custody in Brooklyn following what she called “one of the most depraved crimes one person could possibly commit against another human being.”

The suspect hasn’t been identified, but the New York Post reported that he is a Guatemalan migrant.

Commissioner Tisch said transit police were doing their normal patrol around 7:30 a.m. in Coney Island when they smelled, and then saw, smoke coming out of an idling F train.

Officers arrived to find the woman consumed by flames. They worked quickly to extinguish the blaze, but she did not survive the attack.

Authorities have yet to publicly provide her identity.

“As the train pulled into the station, the suspect calmly walked up to the victim, who was in a seated position at the end of a subway car … and used what we believe to be a lighter to ignite the victim’s clothing, which became fully engulfed in a matter of seconds,” Commissioner Tisch said during a Sunday evening press conference.

Commissioner Tisch said the suspect stayed behind at the scene and watched as the woman was burned alive inside the train car.

She said the suspect was later arrested after a group of high schoolers spotted him at a subway station in downtown Brooklyn and called police.   

The woman’s death was documented by passersby, and incensed local leaders such as Democratic Rep. Ritchie Torres.

“In New York, dangerous people are allowed to freely roam the subway,” Mr. Torres wrote on X. “Yet the political establishment insists on gaslighting the public with deceptive headlines: ’crime is down’ and ’the subways are safe.’”

The fiery killing on the subway came hours after an argument escalated into deadly bloodshed on a separate train in Queens.

Police said a 69-year-old man stabbed two men in their 20s shortly after midnight Sunday.

One of the men was stabbed in the face, and the other was fatally stabbed in the chest.

Through September, eight people had been killed while riding the rails in New York City, up from five slain through the same period last year.

• Matt Delaney can be reached at mdelaney@washingtontimes.com.