Judge Dale Kimball first heard motions from Mitchell's attorneys over his role as a spiritual leader, along with Wanda Barzee's role in the kidnapping.
Just after 3:00 p.m., Mitchell was brought into the courtroom and began singing.
Elizabeth's father Ed took the stand as Mitchell began singing, and chastised him for perverting religious beliefs to justify what he did to Elizabeth.
"I hope that you will one day be able to repent," said Ed.
When Ed finished, Elizabeth took the stand and gave a statement.
"I know that you know that what you did was wrong," said Elizabeth. "I want you to know that I have a wonderful life. You will never hurt me again."
Kimball then addressed Mitchell, and approved a "vulnerable victim" and obstruction enhancement motions from prosecutors, and handed down the life sentences.
Outside the courthouse, Prosecutor Carlie Christensen said she thought the sentence was fair and "measure of justice" that will ensure that Mitchell wold not be able to repeat such "intolerable cruelty."
Ed Smart also spoke outside the courthouse and thanked prosecutors for their efforts.
Elzabeth then spoke and thanked prosecutors as well.
"I'm deeply, deeply grateful," said Elizabeth. "It's a wonderful outcome. I'm thrilled, and couldn't be happier."
When asked about facing Mitchell in court, Elizabeth said, "One day he will have to be responsible for his actions."
She went on to say, "Brian David Mitchell knew exactly what he was doing."
When asked if she was satisfied that Mitchell had nothing to say about his actions, Smart said, "I heard enough form him during those nine months, and I'm glad I don't ever have to hear anything from him ever again."
When asked about her feeling at never having to face Mitchell again, Smart replied, "Hallelujah!"
Ed and Elizabeth also took advantage of the situation to promote National Missing Children's Day, and highlighted three children missing from other parts of the country.
Sentencing was delayed until May so that Smart could attend the court proceeding after serving a mission for the Church of Jesus Christ of Latter-day Saints in Paris.
Mitchell was convicted of abducting Smart from her bedroom in her parent’s Federal Heights home in June of 2002.
During the trial, Smart testified that Mitchell used religious justification to abduct her from her parents and “take” her as a wife at the age of 14. Mitchell’s estranged wife Wanda Barzee participated in Smart’s abduction, and traveled with them between Utah and California during Elzabeth’s ordeal. She later accepted a plea deal for her role in the kidnapping.
Smart also testified that Mitchell raped her almost daily over the nine months she was in his captivity.
Smart was rescued from Mitchell after the trio was spotted walking along a Sandy, Utah street in March of 2003.
Mitchell and Barzee were arrested as Smart was reunited with her family.
After months of evaluation and legal battles, Mitchell was first declared incompetent to stand trial by a Utah Judge in 2005. In March of 2010, a federal judge declared Mitchell competent, and a trial date was set for November of 2010.
During the trial, Smart described in detail her abduction and the sexual abuse she suffered at the hands of Mitchell, and noted his manipulation of Mormon dogma to justify his actions.
The federal trial, which began on November 8, ended on December 10, when the jury convicted Mitchell for the kidnapping and rape of Smart.
Smart, who had taken time away from her LDS mission in France to attend the trial, exclaimed, “I’m thrilled,” outside the courtroom in response to the verdict.
Mitchell has never attended any of the federal trial from inside the courtroom, due to his disruptive hymn singing. Mitchell was allowed to watch a closed-circuit video feed of the trial in another room in the courthouse.
Wednesday afternoon, just after 1:00 p.m., Mitchell was escorted by guard into the courthouse.
At 2:00 p.m. Elizabeth arrived, accompanied by the Smart family.
Stay tuned to ABC 4 News and ABC4.com throughout the day on Wednesday for live coverage of the sentencing.