Every year, thousands of murders in the United States remain unsolved. On May 12, there are over 300,000 cold cases on the books. But a revolutionary technology -- forensic genetic genealogy -- could change this grim reality.

Many people first heard of this technique in 2018, when investigators used it to find Joseph DeAngelo, better known as the Golden State Killer. He eventually confessed to killing 13 people and raping about 50 women in California in the 1970s and 1980s.

Since then, the use of genetic genealogy in criminal investigations has steadily grown. This past year, it led police to arrest the man accused of raping and murdering Rachel Morin, a 37-year-old mother of five who was found murdered near a running trail in Maryland in 2023. 

The initial inquiry into Morin's death revealed that the killer's DNA matched an unsolved home invasion and assault in Los Angeles -- but even with this match, investigators couldn't identify the suspect. 

For decades, law enforcement relied on the Combined DNA Index System, known as CODIS. Launched by the FBI in the 1990s, CODIS compares DNA samples collected from crime scenes to a database of profiles already in law enforcement's possession.

DNA contains unique data points known as markers, which act like a genetic fingerprint. CODIS examines just 20 of these markers, and if no match is found in the database, the case often stalls.

As a result, violent crimes involving unknown suspects go unsolved. 

The solution: forensic genetic genealogy.

Forensic genetic genealogy also relies on detective work and DNA samples, but it looks for matches using hundreds of thousands of markers instead of just 20. 

This process yields matches to individuals who share some DNA with the suspect. With enough matches, police can find the source of the DNA found at the crime scene.

But police departments often don't have the capacity to conduct forensic genetic genealogy on their own. In Morin's case, investigators turned the DNA evidence over to Othram, a company focused on solving contemporary and cold cases. Scientists there used genetic genealogy to develop new leads, culminating in the arrest of Victor Antonio Martinez-Hernandez, who was just convicted on charges of murder and rape. 

Genetic genealogy has now been used to solve thousands of cold cases. 

The fact that we have this technology now is reason for hope. We can bring closure to families by solving past crimes, and also stop new ones by identifying serial rapists and killers earlier in their trajectories.

But making greater use of forensic genetic genealogy infrastructure wouldn't just bring more criminals to justice. Every case solved quickly means less time and money spent on dead-end leads or long-term investigations.

Currently, however, inadequate funding is preventing many investigators from making full use of genetic genealogy tools. 

The solution has to be more federal support. The Department of Justice already makes grants to help reduce DNA backlogs. But more help is required. The next federal budget needs to have a specific focus on the game-changing application of genetic genealogy. At the same time, lawmakers need to re-evaluate how existing resources are being spent. In many cases, cutting-edge technologies can achieve the same or greater results for drastically less money.

We have the technology to solve crimes and protect the innocent. But we can't do so without the political will to prioritize justice.

Sheriff C. Philip Byers is the former Sheriff of Rutherford County, North Carolina. He worked in law enforcement for two decades. This piece originally ran in the DC Journal.