Asked what New Yorkers should do in a similar situation, Mr. Adams [a former transit police officer] focused on Mr. Neely’s presence on the train, and did not discourage people from seeking to restrain someone. Every New Yorker has a story of witnessing an outburst or a violent episode on the subway and struggling over how to respond: To confront or flee; to intervene when two riders are at odds; to call for a police officer, or to look away.
Many have grown worried about safety on the subway after experiencing violence or reading about it in the news. Others are so accustomed to conflict that they ignore it.... Karim Walker, 41, [who] often rode the trains when he was homeless... encouraged New Yorkers who see a person in crisis on a train to help by calling for emergency services. 'We’re all wired to do fight or flight, but approach the situation with as much impartiality as possible,' said Mr. Walker."
From "A Subway Killing Stuns, and Divides, New Yorkers/After a homeless man was killed on the subway, New Yorkers and elected officials are mourning his death and debating how the city should address mental health and public safety" (NYT).
The article says "There is no indication that he was violent or that he made any direct threats," but the most highly rated comments over there object to that way of putting it: