(CNN) -- Brian David Mitchell, the homeless street preacher who abducted, raped and kept a 14-year-old Elizabeth Smart captive for nine months, was sentenced to life in prison Wednesday. "We believe it is an appropriate, just and long overdue result for our community, for the Smart family and of course, most importantly, Elizabeth," said Carlie Christensen, U.S. Attorney for Utah. U.S. District Judge Dale Kimball issued the sentence Wednesday. A jury found Mitchell guilty in December of Smart's 2002 kidnapping. "Mitchell's heinous conduct, the evidence of his propensity to reoffend mandated such a sentence," Christensen said. Beaming before a group of reporters gathered outside the federal courthouse, Smart, now 23, said she was "thrilled" with the sentence -- the maximum allowable under the law.
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NEW: Smart says she is "thrilled" and pledges to dedicate her life to advocacy
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"Today is the ending of a very long chapter," she tells reporters
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Prosecutors say the sentence is just
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A jury found Brian David Mitchell guilty in December
When they reached @placeholder's remote camp, Smart testified she was "sealed" to her captor in a marriage ceremony, raped and shackled between two trees with a metal cable.