Elizabeth Smart is home with her family at last, her long nightmare at an end. But many questions remain about the nine-month ordeal endured by Elizabeth and her family. 48 Hours Investigates gets the inside story on the investigation, and the heroic role in it played by her little sister, Mary Katherine, age 10. Despite criticism of police handling of the case, top investigator Cory Lyman is smiling. "We'll gladly take the beating for this outcome, you know. We're so pleased that it turned out this way," he told CBS News Correspondent Jane Clayson in an exclusive interview for 48 Hours Investigates