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How DNA evidence linked John D. Miller to April Tinsley kidnapping, murder

FORT WAYNE, Ind. (Fort Wayne’s NBC) – DNA evidence and new technology lead to a breakthrough in one of Fort Wayne’s most notorious cold cases.

John D. Miller, 59, was arrested on Sunday, July 15, in connection to the kidnapping, rape and murder of 8-year-old April Tinsley in 1988.

RELATED: Admitted April Tinsley killer pleads guilty in court

Miller admitted to kidnapping April Tinsley and taking her to his mobile home in Grabill, where he said he sexually assaulted, then suffocated her before dumping her body in a DeKalb County ditch.

Over the years, April’s killer appeared to taunt authorities, scrawling on a barn in 1990 that he killed her, and would kill again.

In 2004, police believe he put threatening notes on girls’ bicycles along with other clues that contained his DNA.

In court on Friday, Miller entered a guilty plea and read a written statement to the courtroom admitting what went down in his Grabil trailer.

The image on the left is Miller’s booking photo from the Allen County Jail. At right is one of the computer-generated images from 2016.

Investigators who worked tirelessly on the case point to advances in DNA technology for the breakthrough, including their work with Parabon Nanolabs. 

Scientists used the suspect’s DNA and compared it to existing DNA databases like and 23andMe.

Using a tool called Snapshot, Parabon investigators can predict what people look like with traces of DNA.

In May 2018, Parabon rolled out a new technology called Genetic Geneology, and linked with Snapshot, these developments helped point investigators to John D. Miller.

Investigators searched for descendants who were related to the suspected killer, created a family tree going back in history, and then built it forward to find the right present-day branch.
They then collected several items from Miller’s home with a search warrant containing his DNA.

When those samples matched one of those collected in the past, detectives made their move.

Steve Armentrout, founder and CEO of DNA technology company Parabon, says it’s rewarding to get an arrest after all their hard work.

“The Tinsley case is a special one to us here at Parabon. It was the first case to which we applied the Snapshot technology back in mid-2014,” Armentrout said.

Sergeant Dan Camp, a retired Fort Wayne detective, worked the April Tinsley case tirelessly for years, keeping her picture in his wallet until the day he retired.

Camp told Fort Wayne’s NBC he knew a suspect would eventually be caught even though it didn’t happen on his watch.

“They gave us the profile of the person that probably killed April. Matches him to a T. 29, white, single? Yeah, the whole nine yards. They hit it right on the head to what John Miller looks like and his characteristics today,” Camp says.

READ MORE: Retired police detective thankful April Tinsley’s mother doesn’t have to go through trial

You can check out Parabon’s 2016 report here:

Kayla Crandall

Kayla Crandall is an Emmy award-winning journalist. She serves as the Social Media and Digital Content Manager at WPTA. Follow her on Twitter @KaylerJayne.

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