A 21-year-old man has been charged in connection to the slashing of a 71-year-old Brooklyn woman on the D train.

It happened Monday in Manhattan around 7 a.m.

Police say Damon Knowles was riding the train when it stopped at the Broadway-Lafayette subway station. They say when the doors opened, Knowles slashed the 71-year-old victim on the left cheek leaving her with a laceration. 

They say he ran away, but was caught on surveillance video tripping over a subway turnstile.

Police say Knowles' girlfriend's grandmother saw the video and recognized the clothing he was wearing, so she called police. 

The 71-year-old woman was treated at the hospital and later released.

Knowles was taken into police custody shortly after midnight on Wednesday. He is charged with assault with intent to cause disfigurement and assault with intent to cause serious physical injury.

Knowles' neighbors say they are shocked about the incident, since he had finished school and recently had a baby with his girlfriend.

Police do not believe this incident is connected with other recent slashings that have happened across the city.