A Mississippi 15-year-old has been sentenced to life in prison for killing her mother and shooting her stepfather. After two hours of deliberations, the jury found Carly Gregg guilty on all counts. Gregg was charged with murder and aggravated assault in the March 19 shooting that killed her mother, Ashley Smylie, and wounded her stepfather, Heath Smylie. She was also charged with tampering with evidence for hiding a security camera after the shooting.