A 15-year-old girl dies after being stabbed at a New Oreans Walmart. Four girls, a 12-year-old, two 13-year-olds and a 14-year old, have been arrested. One of the girls is charged with second degree murder and the other three are charged with principal to second degree murder.  Footage of the stabbing, which was posted on Facebook and Instagram live, showing one girl armed with what appeared to be a knife as the victim approaches and lunges at her.  Video shows the group of girls fleeing the store in a getaway car as one of them screams: 'Just stabbed somebody at Walmart'.Joining Nancy Grace today: Darryl Cohen - Former Assistant District Attorney, Fulton County, Georgia, Defense Attorney Phil Chalmers - True Crime Writer, Counter Homicide Trainer & Criminal Profiler, PhilChalmers.com, Where The Bodies Are Buried Podcast, Author: “Inside the Mind of a Teen Killer” and “The Teen Killer Whisperer.” Dr. Bethany Marshall - Psychoanalyst, Marriage and Family Therapist www.drbethanymarshall.com, Joe Scott Morgan - Professor of Forensics Jacksonville State University, Author, "Blood Beneath My Feet" featured on "Poisonous Liaisons" on True Crime Network Levi Page - Crime Online Investigative Reporter