The Facebook logo appears on a screen | File photo by Richard Drew via The Associated Press, St. George News

DALLAS (AP) — The brother-in-law of a Dallas woman raped and slain more than two decades ago while her infant daughter slept in a playpen nearby has pleaded guilty, bringing an end to a case that was re-opened when that daughter as an adult connected with a long-lost relative who helped her push police for an investigation. Detectives also used Facebook to comb through the family’s relatives, ultimately leading to the man’s arrest in Utah.

Victor Serrano, 40, pleaded guilty to murder Thursday in the death of Manuela Dominguez after DNA from the body connected him to the crime scene, The Dallas Morning News reported. He has been sentenced to 30 years in prison for the killing.

Dominguez’s husband, Manuel Serrano, found her dead in bed, next to their infant daughter sleeping in a playpen. He told authorities that Victor Serrano, his brother, was the only other person with a key to the Dallas apartment. A neighbor also told police that she saw Victor Serrano leave the apartment that day.

DNA taken from Dominguez’s body ruled out her husband, but indicated that a male relative of his would likely be a match. Investigators had initially suspected Serrano, but believed he fled to Mexico after they questioned him.

The victim’s daughter, Daisy Serrano-Dominguez, was only 6 months old at the time of the murder. She didn’t learn of her mother’s death until she was 10 years old, having grown up believing that her stepmother was her biological mother.

Serrano-Dominguez, now 23, used Facebook to locate relatives in an effort to move the case forward. She made contact with a long-lost cousin in 2016, and the pair went to the police to see if officers would look into the cold case once more.

They met with Dallas Police Detective Noe Camacho, who also turned to the social media site to track down the Serrano family. He located a known alias of Serrano, which led to Serrano’s arrest last year in Utah.

Written by THE ASSOCIATED PRESS.

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