Rider stabs fellow straphanger in head during dispute on NYC train in disturbing scene

A straphanger stabbed a fellow rider in the head on a Manhattan train moments after it pulled into a crowded station last week, cops said. 

The 26-year-old victim started arguing with the other man after noticing the man was taking a photo of a female rider without her knowledge as the train approached the 125th Station in East Harlem around 11:20 p.m. Aug. 12, police said. 

“Back the f–k up,” the suspect snarled to the man before moving into another car, cops said.

But then once the train pulled into the station, the suspect got off, walked onto the platform and stepped back into the victim’s car, where he knifed him in the left temple, cops said. 

Video released by police late Thursday shows the suspect lunging into the train from a crowded platform to attack his victim as others were getting on board. The suspect then fled. 

The victim was taken to Harlem Hospital in stable condition.