A small-town girl married to a Marine starts an affair with a fellow Marine and meets an untimely death, but was she murdered by her husband or her lover?  Today, Dr. Oz speaks to True Crime journalist Shanna Hogan, along with friends and family members about how this twisted love triangle turned into murder.  Plus, we take an inside look at the police interrogation tapes that involve a confession you have to see to believe.

Then, Sunday school sickos: horrific stories of religious teachers and leaders secretly preying on children.