Adah Pearson
One of the victims, Adah Pearson. Find a Grave photo

A man charged with murder in connection with the shooting deaths of a young couple and a toddler in Normal Heights more than two decades ago pleaded not guilty Friday.

Sergio Lopez Contreras, 44, is accused in the Sept. 4, 2000, killings at a Bancroft Street apartment.

Police responded shortly after 11 p.m. and inside the apartment found the body of Michael Plummer, 20.

Plummer’s girlfriend, Adah Pearson, 18, and Plummer’s nephew, 21-month-old Julio Rangel, were taken to hospitals, where they were later pronounced dead.

The child’s parents were present when the shooting took place but were uninjured, according to police.

Detectives determined that the killings “stemmed from a drug sale gone bad,” SDPD Lt. Jud Campbell said.

Contreras, who was 22 at the time of the shootings, was believed to have fled to Mexico. He was arrested in Mexico on unrelated charges and extradited to San Diego this week.

Police did not disclose when and how he was identified as a suspect in the killings, but prosecutors filed charges against Contreras in 2007.

A criminal complaint indicates he is charged with three counts of murder, along with allegations of discharging a rifle. He is also facing special-circumstance allegations of lying in wait and committing multiple murders, meaning he could face either life in prison without the possibility of parole or the death penalty, should prosecutors pursue it.

City News Service contributed to this article.