"I felt like hope was walking out the door," Smart testified. "I was mad at myself that I didn't say anything. I was mad at myself for just not taking the chance, that I just felt like I was so close, and I felt terrible. I felt terrible that the detective hadn't pushed harder, that he had just walked away."
Smart's physical ordeal ended on March 12, 2003, when she was spotted walking down a Salt Lake City street with Mitchell and Barzee.
Barzee eventually pleaded guilty to her role in the kidnapping and in May 2010 was sentenced to 15 years in prison.
The case dragged on in state courts for years amid legal fights over Mitchell's mental competency.
He was often removed from courtroom proceedings for singing hymns or screaming at judges.
During his federal trial last fall, his attorneys argued Mitchell was not guilty by reason of insanity. A jury rejected that argument and in December found him guilty.
ABC News producer James Nelson.contributed to this report.