"48 Hours" correspondent Peter Van Sant and field producer Kat Teurfs discuss the case against John Blauvelt on "Post Mortem." Blauvelt, a one-time military recruiter, went on the run with his teenage girlfriend after stabbing his wife Cati to death. When U.S. Marshals finally tracked him down six years later, Blauvelt was using a different name and living with a new girlfriend across the country. Watch the team discuss the murder weapon, the pirate tattoo authorities used to identify Blauvelt and the journal where he wrote "I did it."