48 Hours correspondents Anne-Marie Green and Peter Van Sant are joined by journalist Sheila Flynn to discuss the murder of Kristil Krug, a Colorado mother of three. They explore the threatening messages Kristil received for months before her death by an alleged stalker and how investigators used digital forensic evidence to determine that stalker was her own husband, Dan Krug. Sheila attended the trial and gives insight from the courtroom. Peter shares why Kristil’s ex-boyfriend, who was the initial suspect, had a rock-solid alibi.