Salt Lake City (CNN) -- The jury began deliberations Thursday in the trial of Brian David Mitchell, accused of kidnapping 14-year-old Elizabeth Smart in 2002.
The jurors will decide whether Mitchell, 57, was legally insane when he snatched Smart at knifepoint from her bedroom on June 5, 2002.
Smart testified at the monthlong trial that he led her to a makeshift camp in the canyons above her home, "sealed" her as his spiritual plural wife and raped her.
U.S. District Dale Kimball instructed jurors that in order to acquit Mitchell under the insanity defense, they must determine he was mentally ill and that his illness was so severe it kept him from knowing right from wrong.
Defense attorneys mounted the insanity defense for Mitchell, trying to convince jurors that Mitchell was so delusional he could not understand his actions were wrong when he abducted Smart. Several mental health experts testified for the defense, offering diagnoses that ranged from delusional to psychotic to paranoid schizophrenic.
Prosecutors produced their own mental health experts, who testified that Mitchell was little more than a narcissistic pedophile who used religious dogma and claims he received revelations from God to get what he wanted.
Smart spent nine months with Mitchell and his legal wife, Wanda Barzee, at makeshift camps in the Utah mountains and at a homeless camp outside San Diego, California.
Now 23, Smart was the star witness for the prosecution. She said Mitchell raped her nearly every day of her captivity, some days more than once. She initially was kept tethered between two trees and treated "like an animal," she testified. Later, she was allowed to accompany Mitchell and Barzee into town, but was forced to wear flowing religious robes and a veil. She was not permitted to speak to other people, she said.
Mitchell claimed to be a prophet named Immanuel David Isaiah, who would take 49 wifes and battle the Antichrist in the end times. Afterward, his family would hold exalted positions in the new kingdom.
Smart said her job was to teach the new wives how to perform sexually. She said Mitchell claimed she was preordained to be his wife but never spoke of his destiny with outsiders. Many times, she said, he used his revelations to justify drinking, smoking or viewing pornography.
Mitchell, Smart and Barzee were stopped by police in Sandy, Utah, on March 12, 2003. Smart was reunited with her family, and Mitchell and Barzee were charged by state authorities. When those cases bogged down over whether they were mentally competent to stand trial, the case moved to federal court.
Barzee, 64, reached a plea bargain and is serving 15 years in prison. She testified for the defense and described Mitchell as a manipulator who took advantage of her religious beliefs.
CNN's Lena Jakobsson and Ann O'Neill contributed to this report.