Cyntoia Brown isn't going to be released any time soon.

Cyntoia Brown, the Nashville woman who was imprisoned at the age of 16 for killing a child predator who paid her for sex, will not be eligible for release until she serves 51 years in prison.

The decision was unanimously made on Thursday by the Tennessee Supreme Court, with the court's five justices stating that  Brown can't become eligible for release before serving more than five decades.

In a report from CNN, the court explained in a statement that "under state law, a life sentence is a determinate sentence of 60 years. However, the sixty-year sentence can be reduced by up to 15 percent, or 9 years, by earning various sentence credits."

Recognition for good behavior and participation in educational or vocational training programs are among those sentence credits. Brown had previously argued that her sentence was unconstitutional, citing a 2012 opinion by the U.S. Super Court stating that mandatory life sentences without parole for juvenile offenders violates the U.S. constitution.

Prior to this, the Tennessee Prison Parole Board had offered a divided response to granting Brown clemency. Two members were for letting Brown out, two other members were recommending to keep her in jail and two members wanted her conviction to second-degree murder with a 25 year sentence and eligibility for parole after 25 years. Brown has already served 14 years.

Several months ago, Tennessee Governor Bill Haslam granted clemency to four people, three of which were already out of prison. However, Brown was not a part of those given clemency.

The incident with Brown originally took place back in 2004 when she was picked up by Nashville, Tennessee, real estate agent Johnny Mitchell Allen.

Brown admitted that she shot and killed Allen but did so because she feared he would kill her. However, prosecutors argued that Brown robbed Allen after she killed him, with his pants, wallet, and some guns in her possession when apprehended. Ultimately, she was sentenced to life in prison, only eligible for parole after serving 51 years.

Source: CNN