A Montana family's decades-long search for answers in teen's death

For almost 30 years, the death of Danni Houchins had been shrouded in mystery. Hours after the 15-year-old Montana girl disappeared during a walk by a river, her body was discovered face down in a swamp. Investigators first said they may have been dealing with an accidental death. As "48 Hours" correspondent Peter Van Sant reports, years later her family would learn the truth — and a much darker story emerged.