Police are focusing their efforts on an "all-out manhunt" to find the man who shoved a subway passenger to his death on Sunday. And they have apparently identified the person of interest.

According to the Post, "The suspect was identified as homeless thug Kevin Darden — who has more than 30 arrests, including for trying to set his brother’s house on fire. The 35-year-old vagrant, who has done at least one stint in prison, was most recently arrested Nov. 9 in Midtown for pick-pocketing, sources said."

On Sunday, at the 167th Street D train in the Bronx, Wai Kuen Kwok and his wife were waiting for a subway to take them to Chinatown. (They were reportedly going to buy groceries and have lunch to celebrate her birthday.) At 8:45 a.m., when a southbound train pulled into the station, Kwok was shoved into the train's path.

The train's operator, James Muriel, described the awful incident to the Post, "I see a body flying across the tracks. I knew that it wasn’t an ordinary jump on the tracks. The guy didn’t go straight down, he was actually in the air. I slammed the brakes when he was in the air. By the time I got to him he had just fallen onto the tracks, there was just nothing you can do. I need 300-400 feet to get a train to stop. It’s a 100-ton train."

Muriel said that Kwok's body actually hit the windshield, "I then returned to the platform and the victim's wife cried in my arms, begging me for help."

Kwok, 61, was pronounced dead at the scene while his wife was taken to the hospital for trauma. The NY Times reports, "On Monday, Chief Joseph Fox, speaking at a Metropolitan Transportation Authority meeting, expressed sympathy to the family of Mr. Kwok and assured them of a round-the-clock search 'until we identify who did this and bring them to custody,' Mr. Fox said before presenting a monthly safety report."

Darden was spotted getting onto a Bx35 bus after the incident. Police released surveillance video of him:

Muriel also told the Post, "I would like to apologize to the family. There was nothing I could have done."