A Bronx thug convicted of killing a 17-year-old girl by firing aimlessly into a crowd will not be crossing paths with anyone for a long time.

A judge sentenced Brandin Santiago, 21, to 75 years in prison for opening fire outside a house party he attempted to crash. His fury killed Nadairee Walters, a prep student who simply walked out of the party at the wrong time, and injured two others.

The case terrified witnesses and Walters’ family even as Santiago was on trial. One witness preparing to testify, Theodore Edwards, was beaten up and shot by unknown assailants in what prosecutors called a case of witness intimidation.

Extra security surrounded Santiago and the victim’s family members Wednesday, as it did for much of the trial. Notes recovered from his jail cell showed Santiago attempted to order executions while imprisoned.

The girl’s mother, also named Nadairee Walters, spoke at the sentencing, urging the judge to lock up a man she said “had no remorse for anybody.” Santiago appeared nonchalant as she said his “heart is blackened.”

“I got justice for my kid, but I also got justice for the people in the Bronx who will never have to cross your path,” Walters said.

Santiago maintained that his bullets did not hit Walters or the two men when he spoke very briefly.

“I just want to say to my family that I love them and that I am innocent,” he said.

Judge Ann Donnelly ultimately sentenced him to 25 years to life on the murder charge, with 25 years for each attempted murder charge. The sentences will be served consecutively.

“From your prison cell, you plotted to intimidate people and plotted to kill again,” Donnelly said. “You were trying to undermine the system of justice.”