NEW YORK -- A man accused of shoving a stranger in front of a New York subway train was awaiting a court appearance on a murder charge Wednesday, the district attorney's office said.

Kevin Darden, 34, was picked up by detectives Tuesday near his mother's home. Police said he has a history of arrests for assault and robbery, including a pickpocketing charge on Nov. 9 -- one week before authorities say he pushed Wai Kuen Kwok off a subway platform in front of a train.

Darden is also a suspect in a separate incident in which a man was pushed to the ground at another subway station earlier this month. Charges are pending in that case, police said.

Kwok was standing with his wife on a subway platform Sunday when he was pushed from behind by a man. Kwok, 61, was struck by an approaching train and died at the scene. His wife wasn't injured.

There was no indication that Kwok knew the man or had had any interaction with him before he was pushed, police said.

The train's motorman, James Muriel, told CBS New York that he hit the brakes while the victim was still airborne, but it was no use. "We could feel the bumps underneath the train," he said.

Darden fled the station and two minutes later hopped on a bus with other people who had been on the platform at the time of the push and unknowingly discussed it while he was nearby, police said.

Surveillance footage shows the man walking calmly from the subway station. Later footage shows him getting off a bus 10 blocks away, heading into a convenience store and then emerging smoking a cigarette.

The victim's wife was taken to a hospital for observation. Relatives told authorities Kwok worked for a kitchen supply company and the couple was planning to have breakfast and do grocery shopping in Chinatown on Sunday.

About 5 million people ride the subway every day in New York City. Every year, about 140 people are hit by city subway trains, many of them in accidental knocks and wilful leaps. Fifty people have been killed by subway trains this year, and 55 died last year, the Metropolitan Transportation Authority said.