Russell Dermond's headless body is discovered in the garage of his million-dollar lakefront mansion; his wife, shirley, is found floating dead in the water, her ankles tethered with cinder blocks. One key piece of evidence remains missing.

6-year-old Timmothy Pitzen vanishes after a three-day trip to waterparks and the zoo with his mom. In a terrifying twist, his mom is found dead in a motel room with a disturbing note by her side.

Three young brothers are reported missing the day after Thanksgiving in 2010. In a shocking twist, their daddy claims he gave them to an underground group -- but investigators say his story doesn't add up.

After 7-year-old Kyron Horman's stepmother drops him off at a school science fair and takes a picture, the little boy is never seen again; his disappearance is one of the largest mysteries and investigations in Oregon's history.

In 2011, baby Lisa Irwin goes missing from her crib in the middle of the night and is never found. Stolen cell phones and a disturbing charge on a parent's debit card adds to the mystery.

After leaving a friend's hotel, 17-year-old Brittanee Drexel suddenly disappears during spring break in Myrtle Beach; the case comes alive when twisted and disturbing details start to emerge from a prison cell.