Forensic Science Investigation Hub

Genetic Genealogy and the Cold Case Revolution

· 6 articles in this investigation

Summary

Investigative genetic genealogy is the forensic technique that closed the Golden State Killer case in April 2018 and has since resolved more than 650 additional cold case homicides and unidentified remains cases. The method uploads a crime scene DNA profile to public genealogy databases, identifies distant relatives of the unknown subject, and builds family trees forward through descendants until a single candidate emerges. This hub indexes the pillar explainer, the landmark case profiles, the related forensic method of DNA phenotyping, and the queue of unresolved cases waiting for analysis.

Table of Contents

The Method That Rewrote Cold Case Investigation

On April 24, 2018, Joseph James DeAngelo was arrested outside his home in Citrus Heights, California. He was the Golden State Killer, and he had been uncatchable for forty years. Three months earlier, investigators had uploaded his DNA to a public genealogy database. The arrest that followed was not the end of a hunt. It was the beginning of a methodology.

Investigative genetic genealogy has since closed more than 650 cold cases. The method has named killers, named victims, and in some cases named both in the same investigation. It has exposed the limits of traditional cold case work, which depended on a suspect having a criminal history sufficient to place them in a law enforcement database, and replaced it with a search space that expands every time another million consumers upload their genomes to a genealogy site.

This hub organizes the coverage by function. The pillar explainer covers the full methodology, the landmark outcomes, and the legal framework. The case profiles trace specific investigations and what each proved. The DNA phenotyping article covers the adjacent but distinct forensic method of predicting appearance from genetic data. The survey of candidate cases tracks what the method is likely to close next.

The Cluster

What the Hub Tracks Going Forward

The category this hub covers is not static. New identifications land at a rate of roughly one hundred per year, and the list of candidate cases shrinks and regenerates as samples are tested, as databases grow, and as state-level legislation adjusts the boundaries of permissible searches. Case profiles will be added as resolutions are announced, and the forward-view piece will be updated quarterly as the pipeline shifts.

Articles in This Investigation

1

Cold Cases Solved by Genetic Genealogy: 650+ DNA Breakthroughs

Explore how genetic genealogy has solved 650+ cold cases since 2018. From the Golden State Killer to Bear Brook, see how DNA databases crack cases.

 2

Golden State Killer: The Case That Proved Genetic Genealogy Works

Joseph DeAngelo terrorized California for a decade, then vanished for 40 years. A GEDmatch upload in April 2018 ended the hunt in three months.

 3

Bear Brook Murders: DNA Names the Allenstown Four and Their Killer

Four bodies in two barrels in a New Hampshire state park, undiscovered for 15 years. Genetic genealogy finally named the victims and the killer: Terry.

 4

Boy in the Box: Joseph Augustus Zarelli Identified After 65 Years

America's Unknown Child lay in a Philadelphia potter's field for 65 years. In December 2022, genetic genealogy gave him his name: Joseph Augustus Zarelli.

 5

DNA Phenotyping Explained: How Police Predict a Suspect's Face from DNA

DNA phenotyping predicts hair color, eye color, skin tone, and ancestry from a crime scene sample. Here is how the science works and where it fails.

 6

Unsolved Cold Cases Genetic Genealogy Could Solve Next

Dozens of high-profile cold cases sit on forensic shelves with DNA profiles waiting for a genealogy search. These are the cases next in line.

Frequently Asked Questions

What is investigative genetic genealogy? ▼
Investigative genetic genealogy (IGG) is a forensic technique that uses public consumer genealogy databases to identify suspects or victims from crime scene DNA. A SNP profile is generated from the sample, uploaded to GEDmatch or FamilyTreeDNA, and matched against the millions of users who have voluntarily uploaded their own data. Distant cousin matches allow genealogists to build family trees spanning generations and narrow candidates by age, geography, and physical description.
Which cases make up the genetic genealogy cluster on this site? ▼
The pillar explainer on cold cases solved by genetic genealogy, the Golden State Killer case profile, the Bear Brook murders investigation, the Boy in the Box identification of Joseph Augustus Zarelli, the DNA phenotyping explainer, and the survey of unsolved cases that are credible near-term candidates for resolution.
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