A brute who broke a 71-year-old’s jaw in an unprovoked attack on a Brooklyn sidewalk is in custody, police said Tuesday.

Chief Dermot F. Shea announced the arrest on Twitter Tuesday evening.

The suspect, 27-year-old Jaquan Whittle, allegedly walked up to the elderly woman on New York Avenue near Lefferts Avenue at about 5:30 p.m. Sept. 19 and sucker-punched her, cops said.

Whittle, of Flatbush, was arrested for assault on Tuesday, cops said.

He has one previous arrest for attempted rape in 2017, authorities said.

In that attack, Whittle allegedly followed a 23-year-old woman into the Prospect Park subway station in Brooklyn and began harassing her.

“You look like a ho!” he told her as they were entering the station, police said at the time. “I could rape you right now.”

He then grabbed her buttocks as she was going through the turnstile.