It was a Monday afternoon and a 30-year-old man was ranting on an F train headed through Manhattan. He was a regular on the subway, once a gifted Michael Jackson impersonator, but he was also troubled. City workers had tried to help him for years.

Inside the same car was a 24-year-old Marine veteran. After the military, he had dropped out of college, posting online about feeling "completely unfulfilled,” and now he was looking for a bartending job in New York City.

The man behaving erratically, Jordan Neely, was homeless. He shouted to others on the train that he was hungry, that he didn’t care about returning to jail, that he was ready to die, witnesses said.