Nine Americans, including three mothers and six children, are brutally gunned down in Mexico. Police say the family, traveling to a wedding, were killed execution-style. Mystery surrounds the massacre as authorities search for the killers.Who killed the faith-based family and why? Did Mexican cartel members shoot them for revenge? Is it a case of mistaken identity?Joining Nancy Grace to discuss the case:Wendy Patrick - California prosecutor Joe Scott Morgan - Forensics Expert, Professor of Forensics & Author of "Blood Beneath My Feet"Dr. Kendall Crowns - Medical Examiner of Travis County, Texas   Dr. Debbie Joffe-Ellis - Psychologist, Adjunct Professor at Columbia University,  James Gagliano - International Crimes Expert, Former FBI supervisory special agent attached to Mexico for 2 yearsAlexis Tereschuk - RadarOnline Reporter