By EMILY SHAPIRO, ABC News

(NEW YORK) — Survivors of Joseph DeAngelo, the man now known as the “Golden State Killer,” are expected to address him directly in court this week as the killer, who was on the run for decades, appears for his sentencing hearing.

DeAngelo pleaded guilty to 13 counts of first-degree murder in front of dozens of victims and victims’ relatives in June as part of a plea deal, which also required him to admit to multiple uncharged acts, including rapes, which were described in horrific detail by prosecutors.

The death penalty was taken off the table in exchange for the guilty pleas — DeAngelo will be sentenced to life without parole.

The sentencing hearing, which will include statements from survivors and victims’ families members, begins Tuesday.

DeAngelo, now 74 years old, was accused of committing 13 murders as well as multiple rapes and burglaries in the 1970s and 80s, terrorizing communities from Northern to Southern California.

The “Golden State Killer” crimes went unsolved until April 2018, when DeAngelo was arrested in Sacramento County.

DeAngelo became the first public arrest obtained through genetic genealogy, a new technique that takes the DNA of an unknown suspect left behind at a crime scene and identifies him or her by tracing a family tree through his or her family members, who voluntarily submit their DNA to public genealogy databases. This allows police to create a much larger family tree than using law enforcement databases.

To identify DeAngelo, investigators narrowed the family tree search based on age, location and other characteristics.

Authorities conducted surveillance on DeAngelo and collected his DNA from a tissue left in a trash. Investigators plugged his discarded DNA back into the genealogy database and found a match, linking DeAngelo’s DNA to the DNA found at multiple crime scenes, prosecutors said.

Since DeAngelo’s arrest, over 150 other crime suspects have been identified through genetic genealogy.

Copyright © 2020, ABC Audio. All rights reserved.