Here's how DNA evidence led to the capture of the elusive serial killer:
1. Early Investigations: Following the Golden State Killer's attacks in the 1970s and 1980s, law enforcement collected forensic evidence, including DNA samples, from the crime scenes. These samples were stored and preserved for potential future analysis.
2. Advancements in DNA Analysis: Over time, DNA analysis technology evolved significantly. As techniques such as DNA profiling, polymerase chain reaction (PCR), and genetic genealogy gained prominence, it became possible to extract more information and generate more accurate DNA profiles from old and degraded samples.
3. Renewed Interest in Cold Cases: In 2017, detectives decided to revisit the decades-old Golden State Killer case. They collaborated with Parabon NanoLabs, a DNA analysis firm, to apply modern DNA analysis techniques to the preserved DNA evidence from the crime scenes.
4. Genetic Genealogy and Partial Match: Parabon NanoLabs created a DNA profile from the crime scene evidence and uploaded it to a public genetic genealogy database. The profile had partial matches with some individuals, suggesting a distant genetic relationship between the suspect and the members of the database.
5. Family Tree Investigation: The detectives and Parabon NanoLabs began constructing family trees based on the partial matches. They painstakingly compared DNA data, built genealogies, and followed leads to identify relatives and descendants of the suspect.
6. Narrowing Down the Search: As the investigation progressed, the detectives narrowed down the suspect pool to several potential individuals who matched the DNA profile and had connections to the areas where the crimes took place.
7. Joseph DeAngelo: In April 2018, after extensive genealogical research and covert surveillance, the investigators focused on Joseph James DeAngelo, a former police officer living in Citrus Heights, California. He became the prime suspect based on the DNA evidence and other investigative findings.
8. Confirmation and Arrest: To confirm DeAngelo's identity, law enforcement obtained a covert DNA sample from his car door handle and compared it to the crime scene DNA. The DNA profiles matched, providing overwhelming evidence of his involvement in the Golden State Killer crimes. DeAngelo was arrested on April 24, 2018, at the age of 72, putting an end to the long-unsolved case.
9. Subsequent Trials and Sentencing: DeAngelo faced multiple trials and eventually pleaded guilty to 13 counts of first-degree murder, 13 counts of kidnapping, and one count of attempted murder. In June 2020, he was sentenced to life in prison without the possibility of parole.
The application of advanced DNA technology and genetic genealogy ultimately proved instrumental in solving the Golden State Killer case, bringing long-awaited justice to the victims and their families.
