A man was arrested for fatally shooting his girlfriend and her 26-year-old son inside their Brooklyn home over the weekend, police said.

Luis Collado, 52, was charged with two counts of murder Saturday for allegedly gunning down Rosa Acevedo, 43, and her son Gustavo Devora Acevedo in East New York, according to the NYPD.

Police found Rosa and Gustavo with multiple gunshot wounds at their residence on Louisiana Avenue just before 7 p.m. on Friday.

The mom died at the scene, while her son succumbed to his injuries at Brookdale Hospital Medical Center on Saturday, cops said.

Collado was taken into custody for questioning shortly after the shooting, with investigators noting that they recovered a firearm at the victims’ home.

Along with the two murder counts, Collado was also booked for attempted murder and three counts of criminal possession of a weapon.

What led to the shooting remained unclear, with the NYPD saying that the investigation was ongoing.

The Acevedos’ murders occurred within hours of two other shootings in Brooklyn on Friday night.

In Bedford-Stuyvesant, a 64-year-old man died after being riddled with gunfire in front of 445 Pulaski St., shortly before 9:40 p.m., police said.

Over on Cypress Hill, a 17-year-old boy was shot in the back on Jerome Street and New Lots Avenue at around 7:45 p.m., cops said.

The teen was transported to Brookdale Hospital in stable condition, police said.