Five years after Justin Ross Harris left his toddler son inside a hot car for eight hours, he's asking for a new trial. His lawyers calling the first 'unfair.' The little boy experienced a horrific death, slowly dying inside a scorching hot car on a summer day. Harris even returned to the car during lunch to place some items inside, yet he claimed he didn’t notice his son strapped inside a car seat in the vehicle.Was it a tragic accident, or a calculated killing?Nancy's expert panel weighs in:Kathleen Murphy:  North Carolina Family AttorneyVincent Hill:   Private InvestigatorDr. Jolie Silva:    Forensic psychologistDr. Michelle Dupre:    South Carolina Medical ExaminerRobyn Walensky:   Crimeonline.com Investigative Reporter