This alleged killer, smirking Friday as he was led out of a Brooklyn station house, coldly said, “I don’t give a f–k. I’m here and they not.’’

Allen Cooper, wearing new bracelets, made his vile comment as he was being put into a police car outside the 88th precinct for trip to Central booking, where he was charged with slaying three men — including a 76-year-old innocent bystander — in a drug dispute.

Cops said Cooper, 31, had been laying claim to his territory in the courtyard of the Ingersoll Houses in Fort Greene at about 1:50 a.m. on Sept. 20, 2015, when he fired nine rounds at his rivals.

Calvin Clinkscales, 45, and 39-year-old Lacount Simmons were declared dead at the scene.

Herbert Brown, who was in the wrong place at the wrong time, died at Methodist Hospital.

Cooper — who shortly afterward was identified as the suspect — fled to North Carolina, where he had been hiding out until last week.

“On April 15, last Friday, . . . we got an anonymous call from a female indicating that Allen Cooper was in Fayetteville, North Carolina,” said Sgt. Richard Erickson, squad commander of the 88th Precinct.

Local authorities apprehended Cooper at his lady friend’s apartment — and he was extradited to New York on Friday to face three charges of murder.

The career criminal, who has priors including attempted murder and robbery, has refused to make any statements.

“He declined to speak,” said Erickson, adding, “There is video evidence and eyewitness evidence.

“He’s a bad individual.’’

Gina Hall, Brown’s widow, told The Post the day after the shooting, “I was on the phone with [Herbert] just before. He told me to stay inside.

“All I heard was [someone yelling] ‘Yo!’ and then the shooting started.’’