(NewsNation) — Cold case investigators have turned to forensic genetic genealogy to try to identify potential suspects from DNA in public databases like ancestry sites that have tens of millions of users worldwide.

In fact, this fairly new technique is how Bryan Kohberger was named as a suspect in the University of Idaho killings. It was also how the Golden State killer, Joseph James DeAngelo Jr., was caught.

So far, more than 400 cases have been solved using forensic genealogy, according to a report by The Institution of Engineering and Technology.

The problem is that it’s expensive for local law enforcement agencies.

Now, Texas Sen. John Cornyn is introducing a bill that would provide federal funding for it.

These tests can cost thousands of dollars, and this funding would give investigators across the U.S. more access to try to crack cold cases.

While there are some concerns about privacy, investigators say this could be huge for so many people who have waited years for answers.

“Quite frankly, that’s where this money needs to be,” NewsNation law and justice contributor Jennifer Coffindaffer said.

The government can already check the DNA of those arrested for certain offenses — that all goes into a system called the Combined DNA Index System (CODIS). That way, investigators can check for potential suspects using crime scene data.

When there’s no match, investigators can turn to forensic genealogy.

“The drawback, though, is that individuals who just wanted to know their lineage, now, that information could possibly lead to one of their relatives being implicated,” Coffindaffer said.

This is exactly what happened when Kohberger was named the main suspect in the Idaho killings case.

Investigators used genetic genealogy to link Kohberger to the crime by creating a DNA profile from a knife sheath found at the scene, which matched the profile of Kohberger’s dad, eventually leading to his arrest.

Some ancestry sites, like 23andMe, require a court order to give up their data to law enforcement, and others allow the consumer to opt out.

Besides consumer privacy concerns, attorneys say DNA evidence can be challenged in court.

“It doesn’t tell you when, how or a motive,” attorney David Tarras said. “Any time a prosecutor uses DNA, it’s a supplement to other tools and it’s usually not the best tool.”

Investigators say it’s a balance.

“Being able to solve horrific crimes and murders, being able to protect the public from murders and sexual assaulters and then to also exonerate those who are currently incarcerated, who perhaps that should not be,” Coffindaffer said. “When you look at that balance, it seems like an easy question.”