There is no mystery about who killed Brenda Shaefer. Everyone in Louisville, Ky. knows that Mel Ignatow did it. The mystery is why Ignatow is still a free man. It's a question that has consumed writer Bob Hill. "The guy got away with murder, absolutely got away with murder, and 13 years later, he's still walking around getting away with murder," says Hill. A newspaper columnist for 26 years, Hill was so enraged by the murder that he wrote a book about it: "Double Jeopardy." As Erin Moriarity reports for 48 Hours, the story started on Sept. 24, 1988, when 36-year-old Brenda Schaefer disappeared. Her car was found abandoned the next day less than half a mile from where she lived with her mom and dad.