(InvestigateTV) – Thanks to a breakthrough in how DNA is used, more than 1,000 collective years worth of cold cases across the U.S. have been solved in just the last nine months.

Police are teaming up with genealogists to track killers through their blood lines.

Multiple people are now charged with murder – alleged killers who went undetected for years.

One California case put a spotlight on this technology: the arrest of the man police believe is the Golden State Killer. Using decades-old DNA and re-creating family trees, Sacramento police tracked down Joseph James DeAngelo. He is accused of more than 50 rapes and 13 murders.

That breakthrough set new cold case discoveries in motion at Parabon Nano Labs in Reston, Va.

“You certainly didn’t think of this when you were going to school for genetics and computer science. But we’ve ended up being able to really innovate and make a huge difference for society and for these families,” said Dr. Ellen Greytak, of Parabon Nano Labs.

For two decades, Parabon was building to this moment. It has used its DNA analysis service called Snapshot on unidentified remains, but the lab hadn’t opened up the technology to police files until 2015.

They were also working on genetic genealogy, but wanted to see how the public would react to this new type of science: Would people think it’s ethical?

“When [Golden State Killer] broke, it was a chance to look at how the public would respond to perpetrator cases, to offender cases, and with that positive reinforcement by the public, we decided, ‘OK, let’s go into this not timidly but with full force,’” Dr. Steven Armentrout said, who started at Parabon nearly 20 years ago.

In just the last year, Parabon has helped law enforcement across the country in making positive identifications in nearly 50 cold cases. That’s nearly one cold case a week solved using genetic genealogy.

“This couldn’t have been done even five years ago. There just wasn’t the level of DNA technology. And the databases, even the genealogy research, a lot of that has come a long way recently,” Greytak said.

One of the first big breaks for Parabon was the case of 8-year-old April Tinsley in Fort Wayne, Ind. She vanished in April 1988 while walking to a neighbor’s house.

Her body was found dumped in a ditch three days later. She had been sexually assaulted and strangled.

Over the years, her killer taunted police. In 1990, he scrawled on a barn that he killed Tinsley and would kill again. In 2004, he put threatening notes on girls’ bicycles. The case terrorized the town and stumped police.

“When you read about this, you get so angry that this happened and that they’ve had to wait so long for an answer,” Greytak said.

Parabon was able to narrow the killer down to two brothers, opening the door for police to step in with old-school detective work to nab their suspect. They got samples of each brother’s DNA until they were able to identify Tinsley’s killer.

“That is a collection of emotions that you’re not prepared to deal with because you’re excited about assisting, [but] at the same time you’re dealing with family members who are having to relive these things. It’s a challenging but fulfilling opportunity,” Armentrout said.

Parabon helps police find a match in two different ways: genetic genealogy to match people to family members and DNA phenotyping, which predicts physical appearance.

The lab pioneered that identity prediction technology, which it calls Snapshot, and released it to police in 2015.

“Now Snapshot predicts eye color, hair color skin color freckling face shape and ancestry. We bring all that together to release a composite,” Armentrout said.

On Parabon’s website, police departments give testimonials that the technology has helped move investigations – particularly by helping investigators get an idea of what a suspect looks like.

The DNA gives scientists skin color, eye color, face shape and a certified forensic artist fills in the rest with things like age and weight progression.

The scientists and artists don’t know details like how a suspect wears his or her hair, but they can create a composite that has enough detail to spark a memory or look like someone people knew around the time of a crime.

“It’s almost like the DNA is that witness describing to the artist what it saw,” Greytak said.

The other technology, genetic genealogy, is the groundbreaking way Parabon is breaking open these cases for police by using a public database called GED Match.

The site has been popular with genealogists for years who use it to find relatives. Users who have profiles with popular DNA profile sites like Ancestry or 23andMe have to download their DNA data and upload it to GED Match.

When someone uploads his or her DNA to the site, it indicates the information could be used by police and others for investigations. Users can pull DNA information out at any time.

For solving crimes, Parabon and police then take DNA found at crime scenes and also add it to GED Match. Matches come back for distant relatives, as far removed as third and fourth cousins.

Once those matches are made, the real time-consuming work begins. Genetic genealogists build family trees for each of those matches and look for the right branch of people who share significant amounts of DNA with that unknown suspect.

For Greytak, those moments when she locates a potential suspect are exhilarating – for a brief time, she said only she and the killer know the truth.

“[The suspect] knows what color his eyes are. Now we know,” Greytak said. “We’re all running around the office saying, ‘OK, we need to get them on the phone right now. They need to know. I don’t care that it’s been 30 years. We’re not waiting until tomorrow.’”

For police, genetic genealogy is the biggest crime fighting invention since the discovery of DNA.

“It brings great hope and it brings also a warning to any would-be serial killers or spree killers,” said Mike Jones, a security consultant with 41 years in law enforcement. “Your deeds live forever as long as your DNA is out there.”

Jones took InvestigateTV’s reporter to what used to be a wooded area in Richmond, Va. While standing there, Jones said, “This ground that we are standing on near the Virginia Science Museum, it holds one of my greatest failures in law enforcement.”

The location is near where police found the body of 17-year-old Catena Parker in 1991. She was abducted and murdered. Her killer is still out there.

Like a lot of former detectives, Jones has his one cold case that haunts him. The one he couldn’t figure out.

“It’s personal, it’s highly personal. It’s an unsolved crime, and the killer who we believe we have identified… is still out there roaming around,” Jones said.

He said police across the country are paying close attention to these new DNA detectives.

“They’re saying two things: let’s get the boxes out of the evidence room, and then let’s find the funding for it,” Jones said.

Even when genetic genealogy leads police to a suspect, the work of police isn’t over.

“You still have to prove the case. Nothing stops that ‘proof beyond a reasonable doubt,’ and nothing should,” Jones said.

When detectives knocked on the trailer door of John D. Miller one Sunday in Indiana, they said the 59-year-old already knew why they were there.

He’s now charged with the murder of April Tinsley. Her mother waited nearly 30 years to know who killed her baby girl.

“Chills from the top of your head down to your toes. It’s like you want to believe it than you can’t believe it,” said Janet Tinsley, April’s mother.

Seeing the Tinsley family finally have some answers is why Greytak continues searching through history to find present-day killers who thought they got away.

“Of course we can never help them get over what happened. But hopefully [we can] allow them to at least know there’s going to be justice for their family member,” Greytak said.