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 did n'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 was n'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 ca n'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 .
Brian David Mitchell was a troubled child who grew distant from family , his father testifies . His sister says Mitchell gave up his children but blocked his family from adopting them . Score: 7 Mitchell could face life in prison if convicted in Elizabeth Smart 's kidnapping .