The NYPD has released surveillance footage of the man suspected of fatally pushing 61-year-old Wai Kuen Kwok onto the tracks of the East 167th Street subway station on Sunday. (The attacker, who did not know Kwok before shoving him into the path of an oncoming D train, fled via the Bx35 bus.) In the video, the suspect can be seen smoking a cigarette outside a nearby bodega. He’s black, balding, and dressed in a dark leather jacket and sneakers — and that’s about all the police know about him so far. Information leading to his arrest will be rewarded with $2,000, plus the peace of mind that comes with knowing this guy isn’t still running around the city.