His orange and black Razor bicycle was lying next to his body.
Espinoza-Navarrete was rushed to St. Luke's Hospital, where he was pronounced dead.
Police initially believed he was a bicyclist struck by a car.
But when detectives reviewed nearby surveillance cameras, they found grainy video of two men chasing the victim.
The video apparently shows one of the men ripping off his shirt as he runs after Espinoza-Navarrete. A suspect is then seen fleeing on foot, and returning to pick up a dropped cell phone.
Detectives suspect the actual assault occurred out of the surveillance camera's range.
Espinoza-Navarrete had bruises on the back of his head, but the medical examiner will conduct an autopsy to determine the exact cause of death.
The victim lives near the spot where he was discovered dead, about a half block from CUNY's campus.
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