New York cops are scouring the city to find the man who shoved Ki Suk Han in front of a subway train around 12:30 p.m. Monday, killing him. The incident occurred at the 49th street station in Manhattan.
Surveillance video has been released by detectives in attempts to identify the man.
In the video the two are seen arguing. Allegedly the assailant had been harassing other passengers and Ki was attempting to calm him down.
NYPD spokesman Paul Browne has also said that the man was talking to himself prior to the argument.
Ki Suk Han attempted to pull himself up from the platform, but he was hit by a southbound Q train. He was rushed to St. Luke's Hospital but pronounced dead upon arrival. He is survived by his wife and college-age daughter.
Investigators say the suspect is 20 to 30 years old, 5-foot-9 to 5-foot-10, and 180 to 190 pounds.
Anyone with information on the case should contact the Crime Stoppers hotline at 800-577-TIPS, or text CRIMES and then enter TIP577, or visit nypdcrimestoppers.com.