A 16-year-old boy was charged Friday in two “knockout” assaults that were 40 minutes apart in Deer Park, seriously injuring one of his victims in an unprovoked attack caught on video, Suffolk police said.

The boy’s two accomplices in the videotaped attack were also arrested, police said.

Surveillance camera footage shows the attacker coming up from behind to punch a man walking on Deer Park Avenue about 12:55 p.m. Wednesday. The victim toppled onto the roadway behind a white car parked at the corner — the suspect’s getaway car — and the suspect almost tripped over the fallen man as he ran to open the back door of the car, the footage shows.

The teenager got into the car and took off with Jean Jimenez and Adonis Byers, leaving an unconscious man, his face inches from vehicles rushing past, police said.

The victim, a 60-year-old man from Shirley, suffered several facial fractures, police said. Witnesses helped him, police said, and he was taken to taken to Good Samaritan Hospital Medical Center.

Earlier in the day at the Taco Bell on Deer Park Avenue, the same teenager also escaped after punching an 18-year-old man in the face, knocking him to the ground, police said. The victim’s injuries were not critical, police said.

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The suspect, who was 15 on the day of the attack, was charged as a juvenile with first-degree reckless endangerment, a felony, and two misdemeanor counts of third-degree assault, police said. His arraignment was scheduled for May 25.

Jimenez and Byers, both 16 and from Deer Park, were arraigned Friday on charges of first-degree reckless endangerment and third-degree assault against the Shirley man.

Bail and attorney information were not immediately available Friday night.