New York City police were working Monday to identify the woman who died after being intentionally set on fire inside a stationary subway train as well as more information about a man, now in police custody, who is a “person of interest” in the crime.

Chief of Transit Joseph Gulotta said Sunday that questions about the suspect’s background and whether the victim was homeless were all part of an active police investigation.

Transit police apprehended the man, who has not yet been publicly identified, after receiving a report from three high school students who had recognized the man. They had seen images of the suspect taken from surveillance and police body cam video and widely distributed by police.

“New Yorkers came through again,” said New York City Police Commissioner Jessica Tisch on Sunday. She described the case as “one of the most depraved crimes one person could possibly commit against another human being.”