The teen was blasted in the back around 9:30 a.m. at East 161st Street and Forest Avenue, part of NYCHA's William McKinley Houses in Morrisania, police said. 

“In the Marine Corps, there's a purpose, as a police officer, there's a purpose,” said Det. Second Grade Scot O. Abrams, 52. “There's that pride, you know, of having to be wanted and needed. I love what I do. I want to keep doing what I do. 

The predator approached the preteen around 5:45 p.m. in the stairwell of the Cooper Houses building on Morgan Avenue near Jackson Street in Williamsburg.

William Credle allegedly lured a 15-year-old girl to his home and raped her -- less than two years after being charged with a hauntingly similar attack.

He went on to randomly strike a 34-year-old man just outside the 73-story skyscraper at the corner of East 42nd Street and Vanderbilt Avenue – before storming inside the lobby of the iconic building and dealing another blow to a 23-year-old man, the sources said.