The Locked Door: The Death Of Ellen Greenberg

The apartment was locked. Outside, snow was falling across Philadelphia. Inside, 27-year-old Ellen Greenberg lay dead on her kitchen floor. 

She had 20 stab wounds to her body. What happened next would spark a debate that has lasted more than a decade. Investigators changed their conclusions, forensic experts disagreed, and Ellen's parents began a relentless fight to uncover the truth. 

What really happened to Ellen Greenberg? Was this a tragic suicide, or does one of America's most baffling death investigations still have crucial questions left unanswered?