MINNEAPOLIS >> A man charged in the museum heist of a pair of ruby slippers that Judy Garland wore in “The Wizard of Oz” pleaded guilty today in a deal that could keep him out of prison due to his failing health, but only cleared up some of the mystery that dates back 18 years.

Terry Jon Martin, 76, pleaded guilty to a single count of theft of a major artwork. The shoes were stolen in 2005 from the Judy Garland Museum in the late actor’s hometown of Grand Rapids, Minnesota, and recovered by the FBI in 2018.

No one was arrested until Martin, who lives near Grand Rapids, was charged this year. During his change-of-plea hearing in federal court in Duluth, Martin said he used a hammer to smash the glass of the museum door and display case to take the slippers. He said he thought the slippers had real rubies and that he had hoped to sell the gems. But when a fence told him the rubies were glass, he said he got rid of the slippers.

Martin did not say how he got rid of them or to whom he gave them, leaving the slippers’ whereabouts during the ensuing years a mystery. He did say that the theft had nothing to do with trying to get insurance money, as some have speculated.

“Terry has no idea where they were and how they were recovered,” Martin’s attorney, Dane DeKrey, said afterward. “His involvement was that two-day period in 2005.”

Under the plea agreement, DeKrey and federal prosecutor Matt Greenley recommended that Martin not face any time behind bars because of his age and poor health. Martin, who appeared in court in a wheelchair with supplemental oxygen, has advanced chronic obstructive pulmonary disease and struggles to breathe, DeKrey said. The proposed sentence would let Martin die at home, the attorney said.

“He’s basically slowly suffocating to death,” DeKrey said.

Martin, who has a 1988 conviction for receiving stolen goods, remained free on his own recognizance after the hearing. U.S. District Judge Patrick Schiltz, the chief federal judge for Minnesota, ordered a presentence investigation and said he’d likely schedule the sentencing for about 2 1/2 months from now.

Schiltz told Martin that he isn’t legally bound by the sentencing recommendation by the defense and prosecution. According to DeKrey, the nonbinding federal sentencing guidelines recommended eight to 10 years in similar cases.

The U.S. attorney’s office said it would have no comment until after Martin is sentenced.

Garland wore several pairs of ruby slippers during the filming of the classic 1939 musical, but only four authentic pairs are known to remain. The stolen slippers were insured for $1 million, but federal prosecutors put the current market value at about $3.5 million.

The FBI said a man approached the insurer in 2017 and said he could help get them back. The slippers were recovered during an FBI sting in Minneapolis. The FBI has never disclosed how it tracked down the slippers, which remain in the agency’s custody.

The slippers were on loan to the museum from Hollywood memorabilia collector Michael Shaw when Martin stole them. Three other pairs that Garland wore in the movie are held by the Academy of Motion Picture Arts and Sciences, the Smithsonian Museum of American History and a private collector.

Several rewards were offered over the years in hopes of figuring out who stole the slippers, which were key props in the 1939 movie. Garland’s character, Dorothy, has to click the slippers’ heels three times and repeat, “There’s no place like home,” to return home to Kansas.

Garland was born Frances Gumm in 1922. She lived in Grand Rapids, about 200 miles (320 kilometers) north of Minneapolis, until she was 4, when her family moved to Los Angeles. She died in 1969.

The Judy Garland Museum, which is in the house where she lived, says it has the world’s largest collection of Garland and Wizard of Oz memorabilia.