The fiend who savagely beat a 67-year-old man in a Bronx apartment building elevator was busted by cops Tuesday, authorities said.

Bronx resident Joshua Marrero, 22, was charged with assault for the caught-on-camera beating on Nov. 1 in the building near Southern Boulevard and East 187th Street in the Belmont section of the borough, cops said.

Footage of the attack shows the suspect riding the lift with the 67-year-old.

When the door opens, the suspect turns on the victim and begins raining punches down on him, the video shows.

The victim falls to the ground, but the man continues to sock him with a number of blows.

He then uses his sweatshirt to wipe off the door of the elevator, as if he’s trying to cover up his fingerprints, the video shows.

The victim was treated at a nearby hospital for his injuries.