Police are searching for a man who they say assaulted an elderly straphanger aboard the J train last month.
Investigators say the man seen on surveillance video was riding with his son just before 4 p.m. on December 19.
According to investigators, the 76-year-old victim says the the child fell asleep on top of him at the Alabama Avenue station in Brooklyn.
Police say when the man woke the boy up to ask if he was okay, not realizing he was with an adult, the child's father confronted him and asked why he was talking to his son.
The man then allegedly punched the victim in the face several times before getting off the train at the Cypress Hills stop.
He's described as being 30 to 35 years old, six feet tall, weighing 180 to 190 pounds, and was last seen wearing a black coat and dark colored pants.
Anyone with information on the case should contact the Crime Stoppers hotline at 1-800-577-TIPS, or text CRIMES and then enter TIP577, or visit www.nypdcrimestoppers.com.