Cops have busted the man who posed as a utility worker before allegedly killing a 91-year-old man inside his Bronx garage last week, cops said.

Luis Bonilla, 32, was arrested Monday in connection to the death of Nicolo Rappa and charged with murder, manslaughter, robbery and assault, according to police.

Rappa was found with his hands and feet bound and fatally beaten in a garage at Wickham and Waring avenues just before 1 p.m. on Aug. 3, according to police.

Police sources said Bonilla dressed as a utility worker and was “checking meters” before the alleged slaying.

In the days after his death, police released images of his alleged killer wearing a yellow hardhat, a bright green reflective vest and a black mask outside the home.

Additional images showed the suspect’s white rental flat-bed truck, which was parked outside the home.