Australian man's history of gruesome family murder revealed through DNA test nearly 60 years after his escape from prison

• In 1958, William Leslie Arnold killed his parents and buried them in his back yard.
• After escaping from prison in 1967, he fled to Australia and became a family man.

It took 55 years and an at-home DNA test, but US Marshals have finally closed a cold case after decades of tracking a murderer who killed his parents and escaped from prison.

In 1958, then-16-year-old William Leslie Arnold fought with his parents over taking their car to the drive-in before fatally shooting them both and burying them in the backyard of the family's home. After serving a decade of his life sentence, he and another inmate escaped from the Nebraska State Penitentiary.

The other inmate was caught. Arnold fled, eventually ending up in Australia, where he married and started his own family, claiming that he was an orphan, CNN reported.

Arnold's dark past would have never been discovered were it not for that lie, as the man's son later went looking for more information about his father's unknown past – and ended up with more than he bargained for.

In 2020, in cooperation with US Marshal investigators still searching for the fugitive, Arnold's brother James, who was not home at the time of the murders, submitted a DNA sample using an at-home test kit to a major database such as AncestryDNA or 23AndMe, though investigators have not specified exactly which service was used.

The Guardian reported that AncestryDNA, 23AndMe, and My Heritage, the largest genealogy sites, generally prevent law enforcement from putting crime scene DNA into their systems but, with a family member's permission, such as Arnold's brother, they can submit samples and run searches.

James Arnold's DNA sample sat unmatched for two years when another at-home test kit was submitted, thousands of miles away, and the mystery was finally solved — a close familial match appeared, and had reached out wanting to know more about their relative.

"I'm trying to find out more information about my father. He was an orphan from Chicago," Matt Westover, the Deputy US Marshal for the District of Nebraska who led the investigation, told Insider the email read.

Arnold's son, who remains anonymous, believed he was reaching out to his uncle when the match was discovered in 2022, and connected with Westover instead.

Westover told Insider that connecting with Arnold's son was the "best case scenario" he could have hoped for when he pursued DNA testing on the cold case.

Arnold's son helped investigators piece together the man's life after he escaped from prison. After escaping in Nebraska, Arnold assumed the name John Damon and jumped from Cincinnati, Miami, and Los Angeles, before moving to New Zealand in the 1990s, then Australia years after. He met his wife, raised his four children, and died in 2010 at age 69 with a legacy of a businessman and doting father, per CNN.

"There's no warning label on the DNA test kit telling you that you might not like what you find," the son said, per CNN. "But I don't regret doing it, and I'm glad I now know the truth about my dad. Although it's shocking to know that his life began with a terrible crime, his legacy is so much more than that."