A Bronx man has been nabbed in a decades-old cold case involving the murders of two teens found shot in the head on a school rooftop in East Harlem.

Ramon Solla, 45, was arrested Thursday and charged with the 1995 slayings of Ricky Santiago and Christopher Toro-Rossy — a double homicide resulting from a heroin deal gone bad, prosecutors said.

The boys, both 17, were found with gunshot wounds to their heads on the rooftop of Park East High School at 230 E. 105th St. in the early hours of March 3, 1995. Both were pronounced dead at the scene.

Solla, known as “Ray” or “RB,” was 21 when he allegedly gunned down the teens as part of a conspiracy to distribute more than a kilogram of heroin, prosecutors said.

He is facing two counts of using a firearm to commit murder and two counts of murder in furtherance of a drug crime — charges that could land him a maximum of life in prison or the death penalty, if convicted.

Ricky’s mother, Nellie Santiago, 60, said Solla’s arrest finally means long-awaited closure for her family.

“I hope whatever they’re sticking with him sticks,” she said Friday. “Over the years they’ve arrested so many people … they [police] were saying they had leads and they were arresting people but no one would talk.”

She said Ricky knew his alleged killer “because my son would never go up on the rooftop with someone he didn’t know.”

“I feel bad for [Solla’s] family because he has a family now. And they’re going to be without a dad. And she’s going to be without a husband,” said Santiago. “But I’ve been without a son for 24 years. He’s got to pay.”

The mom and Ricky’s sister, Tiffany Ruiz, 29, remembered the tall teen as a ladies’ man who loved to dance. Ruiz said Christopher was Ricky’s best friend.

“A lot of girls had crushes on him,” recalled Ruiz, who was just 5 years old when her brother was murdered. “I get girls who walk up to me still and say, ‘I used to date your brother.'”

Ruiz remembered the last night she spent with her older brother. She lives in the same East Harlem apartment where she and Ricky, the oldest of six kids, were raised by their grandmother.

“I remember the last night he was here, which was probably the night he died,” Ruiz said. “He was playing with me. I cut my hand and he stopped me from crying.”

Through tears, Santiago said the loss of her son fueled her drug and alcohol addiction. She’s now in recovery and runs Narcotics Anonymous meetings several times a week.

“I just wished he could’ve lived longer,” the mom said. “He would’ve done great things. He was a good kid. Anybody that knew him fell in love with him.”

Solla, who was arrested by the NYPD at his Mott Haven home, pleaded not guilty in Manhattan federal court Thursday and is being held without bail at the Metropolitan Correctional Center, according to online records.

“For more than two decades, the families of Ricky Santiago and Christopher Torro have been waiting for justice,” Manhattan US Attorney Geoffrey Berman said in a statement. “Thanks to the extraordinary efforts of the FBI and the NYPD, Ramon Solla will now face justice for his alleged role in the brutal murder of two teenage boys. We hope today’s arrest brings some measure of comfort to the victims’ families.”

Ruiz added, “I feel like we’re at peace. I feel at peace for my family. They finally get to not sit around wondering who would do this to their son. Justice should’ve been brought a long time ago.”

Solla’s lawyer didn’t immediate return messages.

A woman who answered the door to his apartment said she had no comment.

Additional reporting by Georgett Roberts and Emily Saul