Police say they are still on the hunt for a man who opened fire on the No. 3 train Sunday night and killed a beloved school crossing guard.

Police released a photo of the suspect Thursday morning. They say he was arguing with another passenger when he began firing gunshots as the train approached the Rockaway Avenue station in Brownsville. The bullets struck and killed passenger Richard Henderson, 45.

Elected officials say Henderson died a hero as he was trying to break up the fight.

According to a GoFundMe set up for Henderson's family, he worked as a school crossing guard for more than a decade. He leaves behind three children.

As of Thursday morning, the suspect was still on the loose. Police say he was last seen fleeing the Utica Avenue station Sunday night.

Anyone with information about the case is asked to call police.