Updated

Nicole Eby was 9 years old when she last saw her sister Michella Welch alive—and all these years later, she never knew if there would be a break in the heart-wrenching case.

The 32-year-old cold case is one of several in the last week that have been solved thanks to genealogical sleuthing made possible by the uploading of DNA to an open-source ancestry site that was used to crack the Golden State Killer case.

Nicole and her two sisters were playing at Puget Park in Tacoma, Washington, when 12-year-old Michella disappeared. Her body was found later that night in a makeshift fire pit. She had been sexually assaulted and died of blunt force trauma to her head.

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In 2006, a DNA profile was developed from the crime scene, but there was no initial match in databases.

Earlier this year, Tacoma Police detectives worked with a genetic genealogist named CeCe Moore, affiliated with Parabon NanoLabs, a forsensic consulting firm, to determine that the person had about 9 percent Native American DNA.

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Gary Hartman, at left, was arrested and charged with first-degree murder and first-degree rape in the disappearance of Michella Welch, seen at right. (AP)

When that DNA was uploaded to GEDMatch, an open-source ancestry site, Moore identified someone who shared enough DNA with the person to be a first cousin.

Moore, the DNA expert on “Finding Your Roots with Henry Louis Gates, Jr.,” was able to trace the suspect’s ancestry back to his Native American great-great-grandparents on his father’s side, reports the New York Times.

It didn't take long after that for investigators to find a match after extracting DNA from a crumpled up napkin that Gary Hartman, now 68, had left at a restaurant.

“You always hope they catch the guy. But in the back of my mind [I figured] he's probably dead,” Eby told ABC News. “It's really sad to think that he's been out there living a free life when he cut my sister's life short.”

Hartman, was arrested on June 20 and pleaded not guilty. He has been held on $5 million bond.

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“If you think you can run, you’re wrong,” he said. “If you think you can hide, you’re wrong. If you think that the Tacoma Police Department is going to give up, you’re wrong," Tacoma Police Chief Don Ramsdell said at a June 22 press conference.

“I’m just very thankful that the court system can do its job now and that it was through DNA,” Eby said. “You can't argue with it.”