Ronald Cundiff was convicted of assault and weapons possession in February in connection with the incident that started on an A train in 2019.
He first stabbed a 55-year-old man in the torso on the train following the argument over a seat, as the southbound train approached the Canal Street station in Tribeca.
As police were treating the victim, Cundiff was spotted running from the scene.
Police chased Cundiff, who ran onto Bowery Street, where a 21-year-old good Samaritan, Nicholas Cai, tried to stop him and was stabbed in the shoulder.
“Well I don’t know if it was worth getting cut,” Cai said at the time. “They ran down the other side of the sidewalk, and then they looped around crossing the street, and that’s when I turned around and the guy was charging at me. I just figured I’d try and stop him.”
Police were able to catch up to Cundiff and take him into custody.
Ex-Brit turned Manhattan resident since 2008.