"48 Hours" investigates the unsolved death of Stephen Smith, who was killed in 2015 in South Carolina. The 19-year-old's case went cold for years until 2021 when the high profile murders of Maggie and Paul Murdaugh stirred new interest in his case. Now, Stephen's mother, Sandy, is working with a team of lawyers and experts to find out what happened to her son. Nikki Battiste joins "CBS Mornings" with a preview of her report. Air Date: Nov 24, 2023