Elizabeth Smart is set to give testimony in court about her interactions with homeless street preacher Brian David Mitchell, who abducted her when she was 14 at knife point and held her hostage for nine months in 2002.
A judge ruled that Smart can give testimony on Thursday in a hearing to determine if Mitchell is mentally competent to stand trial.
Smart's testimony will be limited to the facts relating to her kidnapping and subsequent captivity and she will not be able to opine on Mitchell's state of mind.
"None of Ms. Smart's proposed testimony suggests that she will be opining on anything other than her lay observations," the judge said in his ruling.
A prosecutor says Smart will be able to provide important observations regarding Mitchell's behavior, including his preoccupation with sex, his lack of religious focus, his manipulation of others, his ability to lie and how he has rationalized his conduct.
Mitchell was indicted last year on federal charges of kidnapping and coercion of a minor with intent to engage in sexual activity after allegedly taking Smart from Utah to California.