True Crime: Philly Teacher Stabbed 20 Times: Was It Suicide Or Murder?

The controversial death of Ellen Greenberg has rattled minds for years after she was found stabbed 20 times inside her locked apartment, and her death labeled a suicide.

Today, Dr. Oz speaks to Ellen's parents, Josh and Sandee, who believe their daughter was murdered, and for over eight years, have been fighting to change the medical examiner's ruling and investigate her death as a "homicide."  They open up like never before about losing their daughter and the obstacles they've faced looking for the truth.

Plus, Dr. Oz meets the woman who texted her deceased father every day for four years until one day...she got a reply.

Watch THE DR. OZ SHOW, weekdays at 4 p.m. on CBS 62.