Ventura , California ( CNN ) -- A Southern California teen who pleaded guilty to killing a gay classmate was sentenced Monday to 21 years in prison . Brandon McInerney , 17 , will serve time in a juvenile detention center until he turns 18 , at which point he will be transferred to the custody of the California Department of Corrections and Rehabilitation . He will get no credit for time already served , and was ordered to pay $ 10,000 in restitution . In September , a judge declared a mistrial in the case of McInerney after a nine-week trial when jurors said they were hopelessly deadlocked on whether he should be found guilty of manslaughter or murder in the death of Lawrence King . He was set to be retried as an adult . But last month , McInerney agreed to plead guilty to killing King `` under the penal code sections for both murder and voluntary manslaughter , '' as well as to using a firearm in that crime . He will serve 11 years for manslaughter and 10 years for the use of a firearm . McInerney was 14 years old when he brought a handgun belonging to relatives to E.O . Green Junior High School in Oxnard , prosecutors said . He shot the 15-year-old King twice at point-blank range in the back of the head , while both were typing papers in a computer lab for their English class along with two dozen students and their teacher , authorities said . Friends said King , an eighth-grader who lived in a group home called Casa Pacifica , was proud of being openly gay . He liked wearing jewelry and makeup to school and he often wore high-heeled boots with the school uniform . He asked his teachers to call him Leticia instead of Larry . Some students bullied him , pupils said . Other students said McInerney was also subject to some harassment because King had a crush on him and made it publicly known . The victim 's father , Greg King , read a statement in court Monday on behalf of Larry 's mother . `` I will never forgive you for what you did , '' she wrote . `` You have left a big hole in my heart where Larry was . ''
Brandon McInerney , 17 , pleaded guilty to killing 15-year-old Lawrence King . The sentence includes 11 years for manslaughter and 10 for using a firearm . A jury earlier deadlocked on whether to convict McInerney of murder or manslaughter . Victim 's father reads a statement in court .