Passerby is shot in the head as New York police arrest fare dodger

Critics, however, question how the pursuit of a minor offender could have escalated to the point where deadly force was used in a confined space.

Tom Donlon, the city’s acting police chief, ordered a full investigation but added: “Make no mistake, the events that occurred … were the work of an armed perpetrator.”

None of those involved were named by the police.

Jennvine Wong of the Legal Aid Society’s Cop Accountability Project told the New York Times that police put lives at risk by choosing to use “disproportionate force in a confined space.”

In a press conference, NYPD Chief Jeffrey Maddrey said two officers saw a man walk through the barrier without paying.

Mr Maddrey said body camera footage showed the suspect threatening to “kill” officers if they followed him and then confronting them with a knife.

Footage shows a train pulling into the station as the confrontation escalates. Officers fired Tasers at the man – to no effect – as he attempted to board the train before jumping back onto the platform.

“At one point he approaches one of the officers with his knife,” Maddrey said. “The officer steps back, draws his weapon and both officers fire.”

Two passers-by, a police officer and the suspect were hit.

Mr Maddrey said the officer realised he had been shot in the armpit but continued to perform “life-saving measures” on the suspect. Both officers then realised two bystanders had also been hit by gunfire. Two more officers then arrived and treated the injured.

Officials said the suspect had been arrested 20 times and suffered from significant mental illness.

Janno Liever, executive director of the Metropolitan Transportation Authority, said the incident began “because someone with a gun wanted to enter the transportation system, someone who … had a criminal and violent past and had even been charged with possession of weapons.”