NEW YORK - Police have arrested the man they say is behind a violent robbery on the Upper West Side.

Disturbing surveillance video shows the suspect repeatedly shoving and punching an 87-year-old man back on May 13 inside a Citibank on Broadway and 96th Street.

The victim is still hospitalized in critical condition.

His attacker, 50-year-old Matthew Lee, was arrested Thursday and charged with robbery and assault.

Despite video surveillance, he tells NY1 he does not remember the attack.