Dennis Walker was a business man and sports memorabilia collector who collected valuable and historic items belonging to legends such as Babe Ruth, Mickey Mantle, and Pete Rose. Walker allegedly began financial schemes and illegally used investors money to gain a collection, valued at over $10 million. In 1986, authorities obtained a search warrant for Walker's office. Based on evidence found, he was charged with fraud and racketeering. Walker and the collection vanished. Walker’s body was later discovered, though his cause of death was never determined. Millions of dollars worth of the collection has yet to be found. This case first aired on Unsolved Mysteries, on October 12, 1988.