Elizabeth Smart waited more than eight years for the word she heard yesterday.

"Guilty," after a federal jury deliberated five hours to convict street preacher Brian David Mitchell of snatching Miss Smart from her bed, at knifepoint in the dead of night, and repeatedly raping her while he held her captive for nine months.

Smart smiled as the verdict was read, while a bedraggled, bearded Mitchell sat at the defence table, singing hymns with his hands before his chest, as if in prayer.

"I hope that not only is this an example that justice can be served in America, but that it is possible to move on after something terrible has happened," Smart said outside the courthouse hours later.

It was a dramatic end to a tale that captured the nation's attention since she disappeared in June 2002: a 14-year-old girl mysteriously taken from her home, the intense search and her eventual discovery walking Salt Lake City's streets with her captors.

Smart, now 23, flew back from her Mormon mission in Paris to take the stand, and recount her "nine months of hell".

"The beginning and the end of this story is attributable to a woman with extraordinary courage and extraordinary determination, and that's Elizabeth Smart," federal prosecutor Carlie Christensen said outside the courthouse.

"She did it with candour and clarity and a truthfulness that I think moved all of us," she said.

Smart described in excruciating detail how she was woken up one night to the feel of a cold, jagged knife at her throat and was whisked away by Mitchell to his camp in the foothills near the family's Salt Lake City home.

Within hours of the kidnapping, she testified, she was forced into a polygamous marriage with him. She was tethered to a metal cable and subjected to near-daily rapes while being forced to use alcohol and drugs.

The five-week trial turned on the question of Mitchell's mental health.

The thinly built, gray-haired Mitchell was routinely removed from the courtroom after loudly singing hymns and Christmas carols and taken to another room to watch the proceedings on closed circuit TV.

He kept his eyes closed in court and never spoke to anyone, including his lawyers.

His lawyers did not dispute that he kidnapped Smart but wanted him to be found not guilty by reason of insanity. Such a verdict would have sent him to a prison mental hospital.

Prosecutors countered that Mitchell was faking mental illness to avoid a conviction, labelling him a "predatory chameleon".

Smart testified she believed Mitchell was driven by his desire for sex, drugs and alcohol, not by any sincere religious beliefs.

Jurors did not buy the insanity defence, deliberating for roughly five hours to find him guilty of kidnapping and unlawful transportation of a minor across state lines for the purpose of sex.

As the verdicts were read, the shackled Mitchell sat singing about Jesus Christ on the cross. Smart then turned to her mother and both smiled. Elizabeth Smart later hugged prosecutors.

"It's real!" father Ed Smart said on his way out of the packed courtroom, giving a thumbs up.

Smart and her family had hoped for the guilty verdict and a long sentence. Mitchell could face up to life in prison.