Salt Lake City, Utah (CNN) -- The elderly parents of Elizabeth Smart's accused kidnapper testified Wednesday that he was a troubled boy who grew increasingly self-absorbed as a man.
"Brian's a very intelligent person and used that to its full extent in the harassment of the other children and my wife," said Shirl Mitchell, the defendant's father. The elderly witness made his way through the courtroom with a walker, apologizing for being some 30 minutes late because his taxi driver dropped him off outside the wrong courthouse.
The testimony Wednesday painted a picture of a troubled family history, and a Brian David Mitchell who alienated his parents as a boy and shunned his own children as an adult.
Mitchell faces a federal kidnapping charge for abducting Smart in 2002 and holding her for nine months. Smart, now 23, testified earlier in the week that Mitchell told her she was divinely selected to be his wife, kept her tethered to trees in a mountain camp, and raped her repeatedly during the ordeal.
He could face life in prison if convicted.
In his opening statement, defense attorney Parker Douglas described his client's life as mirroring his father's in many ways, including unusual and fervent religious beliefs, but he noted that Shirl Mitchell was never formally diagnosed with a mental illness.
During his testimony Wednesday, the elder Mitchell said his son had been troubled since "in the womb," and was conceived under "unfortunate psychological circumstances for me and my wife."
He was asked whether he had a special connection to his son.
"I didn't have too much connection, maybe that's the trouble," he replied. "He sort of alienated himself, isolated himself, in his own little world, you know. He wasn't very responsive to me."
The father also testified about a time when Brian was 9 or 10, when his father dropped him off in a city park in an effort to teach him a lesson. "I said, 'Now you're going to find your way home, and see how it is to be on your own.'" His son was gone until nightfall, he said. He'd made money taking photographs for Japanese tourists, and used his earnings to go to a double feature at the movies.
"This is typical of Brian. He's smart; 'I'm going to make them worry about me, I'll just stay away all day,' and he did," his father testified.
Irene Mitchell, the defendant's mother, testified only briefly Wednesday afternoon. She struggled with many questions, saying she's in the process of losing her memory.
"I remember my son as a little boy," she said, "and what he is now is not the same person." She said his behavior toward her became so frightening that she obtained a protective order.
During cross examination, she was asked to read from a letter from her son during the time his appearance changed.
"My hair and beard are part of a new act. Sorry I can't be a sweet-looking boy all the time," the letter reads.
A sister of Mitchell's, Kayleen Hill, testified that her brother appeared to blame his own children for his lack of accomplishment, and told her they were undeserving of his love.
Mitchell eventually put the children from his first marriage, Travis and Angela, up for adoption, while preventing his own family members from adopting or having contact with them, according to testimony Wednesday.
Hill said she'd been encouraged for a time when her brother became active in the Church of Latter-day Saints and appeared to live a healthier lifestyle than he had before. While married to Wanda Barzee, however, he once again began to isolate himself from the family and became increasingly narcissistic. "Once he started doing his wanderings with Wanda, especially, he became very distant," she said.
"He would kind of be looking down on other people. He felt that he had a special connection with God."
Prosecutors have held that Mitchell is not sincere in his professed religious beliefs, and is a masterful manipulator.
Defense attorneys so far have called 10 witnesses over two days, including Mitchell's parents, two of his sisters and several friends. They hope to show that Mitchell was so mentally ill when he snatched the Salt Lake City teen that he did not know that what he was doing was wrong.
Their case could include testimony by Mitchell himself, as well as his wife, Barzee, who is serving up to 15 years in prison as part of a plea deal with prosecutors that hinges on her willingness to testify against Mitchell. Barzee was not called to the stand in the government's case, but appears on the defense's witness list.