The 14-year-old was taken into custody Friday and faces four counts of assault, police said.
The teen is believed to be behind at least three assaults in Brooklyn, in the neighborhood of Sheepshead Bay, on Tuesday between 4 p.m. and 8 p.m.
Among the attacks, the teen was seen on surveillance video assaulting a Brooklyn cyclist.
Another attack involved an 81-year-old man who was walking along the street. The suspect had approached him, asking where the bus stop was. As the victim began to give directions, the suspect punched him in the face and fled.
Several minutes later, the suspect and his friends are believed to have approached a man on a sidewalk and punched him, unprovoked.
Less than four hours later, police believe the same group approached a 76-year-old woman, asked her a question, and then punched her.
Each of the victims is said to have sustained bruising to the face. They were treated on the scene.