A man arrested in the 1988 slaying of an 8-year-old Indiana girl after authorities said they linked him to the crime with DNA appeared Monday before a judge who gave prosecutors 72 hours to formally charge him in the child's abduction, rape and killing.

John D. Miller, 59, of Grabill was arrested Sunday on preliminary murder, child molesting and criminal confinement charges in April Marie Tinsley's slaying. The Fort Wayne girl's body was found in a ditch three days after her April 1988 abduction about 20 miles (32 kilometers) away.

Miller is being held without bond and it wasn't clear if he has a lawyer who could speak on his behalf. He's scheduled to appear Thursday in Allen Superior Court for a formal arraignment.

When police arrived Sunday at Miller's home near Fort Wayne, they asked him if he knew why they were there and he answered "April Tinsley," before admitting to her killing, investigators said in a probable cause affidavit. Miller allegedly admitted kidnapping Tinsley and then sexually assaulting and killing her at his Grabill home before dumping her body on April 2, 1988, according to the affidavit.

Investigators examined genealogy databases — the same search method that helped lead investigators in California to alleged Golden State Killer Joseph James DeAngelo in April — in the search for Tinsley's killer, according to the affidavit.

It's still unclear how detectives Brian Martin of the Fort Wayne Police Department and Clint Hetrick of the Indiana State Police used DNA information in the Tinsley case, but the affidavit says they worked with "highly trained genealogist" CeCe Moore, a genetic genealogist.

The Allen County prosecutor's office scheduled a news conference for Tuesday morning to discuss the case.

The affidavit, filed Sunday, says Miller's DNA matches DNA found in used condoms taken from trash at his mobile home on July 9.

Miller's DNA also matches DNA taken from Tinsley's underwear and from three used condoms that were found in 2004 at locations in Fort Wayne and Grabill along with messages the killer apparently left 16 years after the crime, the affidavit states.

Miller wore a blue jumpsuit, his feet and hands shackled as he appeared Monday before an Allen County judge, who asked him if he understood the preliminary charges he faces.

"Yes," Miller replied during the hearing attended by several of Tinsley's relatives, WANE-TV reported.

Paul Helmke, who was Fort Wayne's mayor when Tinsley was slain, said the community always held out hope that there would eventually be an arrest in the disturbing case.

"It was like a gash in the community's heart," he told The Journal Gazette.