A drug deal that was brokered over the internet led to the shooting death of a 21-year-old man Sunday night in the Clearing neighborhood on the Southwest Side, according to Ald. Marty Quinn (13th).

“It was a drug deal that was brokered over the internet that went bad,” Quinn said, repeating information he learned from police.

“An altercation took place between the buyer and seller and that lead to the shooting,” said Quinn.

The drug that was being sold: marijuana, Quinn said.

Emelio Miranda, a 21-year-old from Stickney, was in an alley with two other males when they began arguing and one of the males fired shots at him at 10:22 p.m. in the 6000 block of West 63rd Street, according to Chicago police and the Cook County medical examiner’s office.

He was shot in the head and was pronounced dead at the scene at 10:23 p.m., authorities said.

The shooting occurred near the home of Miranda’s girlfriend and 3-month-old daughter, an officer at the scene told a Sun-Times reporter.

A crowd, most wearing Chicago Bears attire, gathered by the alley shortly after the shooting.

A woman sat on the ground crying as a man embraced her.

“My baby is gone, I’ll never get to see him again,” she said. “Oh god, why did you take my son away from me? Why did you take my son?”

Another woman on the scene was visibly distraught and crying as neighbors brought blankets outside to keep them warm.

Area Central detectives were investigating.