(CNN) -- A federal judge Wednesday sentenced the man who kidnapped Elizabeth Smart to life in prison, prosecutors said.
"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, acting U.S. district attorney in Utah.
A jury found Brian David Mitchell guilty in December of kidnapping Smart in 2002 and transporting the 14-year-old girl across state lines with the intent to engage in sexual activity.
"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.
"As I said during court, and I'll say it again now, I absolutely 100% believe that Brian David Mitchell knew exactly what he was doing when he kidnapped me, and all the events that followed. ... Today is the ending of a very long chapter, and the beginning of a very beautiful chapter for me," she said.