( 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 . `` 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 . Wednesday 's sentencing occurred nearly nine years after Smart was abducted . `` This case demonstrates that the road to justice can be painstakingly long and emotional , '' James McTighe , the FBI special agent in charge of the case , said after the sentencing . `` However , this case also demonstrates that justice will be served no matter how many days , months or years it may take . '' Smart testified for three days during Mitchell 's more than four-week trial . `` I felt that because of what he had done to me , I was marked , '' she said during her testimony . `` I was n't the same . My personal value had dropped . I was nothing . Another person could never love me . '' She testified that she awoke to find a man holding a cold steel blade to her neck on June 5 , 2002 . She was taken from her bed and marched up a rugged mountain path in her red silk pajamas . When they reached Mitchell '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 . She said she was degraded and treated `` like an animal . '' Smart said she was raped nearly every day during nine months in captivity and forced to drink alcohol , smoke cigarettes and watch Mitchell have sex with his legal wife , Wanda Barzee . She was forced to wear robes and a veil in public and was not permitted to speak to other people . She said she feared Mitchell would act on his threats to kill her and her family if she did . She said Mitchell told her their marriage was preordained and that she would be by his side as he took seven times seven wives and successfully battled the Antichrist . They would hold exalted positions in God 's new kingdom , she was told . Smart told reporters Wednesday that she was determined to dedicate her life to child advocacy , `` to help stop and prevent future kidnapping crimes , sexual crimes against children , against anyone . '' She noted that the sentencing also occurred on National Missing Children 's Day . Her father , standing beside her , held up posters depicting several children who were recently abducted . `` I think one of the biggest ways to overcome any trial in life , to heal from any kind of experience , is by helping those around you , because by lifting those around you up , you end up lifting yourself up as well , '' Smart said .
NEW : Smart says she is `` thrilled '' and pledges to dedicate her life to advocacy . `` Today is the ending of a very long chapter , '' she tells reporters . Prosecutors say the sentence is just . A jury found Brian David Mitchell guilty in December .