Investigators uncover startling evidence as they attempt to crack the mystery of Aaron Hernandez, a millionaire NFL superstar with a fiancé and a baby who became a cold-blooded killer.

The ex-NFL star's jailhouse lover speaks for the first time and reveals a bombshell: a never-before-known fourth murder at the hands of the New England Patriot.

In the final chapter, new details emerge about Aaron's suicide as investigators try and determine if the hidden story of brain injuries suffered from playing football were behind his murder spree.