The Tennessee Supreme Court on Thursday ruled that Cyntoia Brown, who was 16 years old when she killed a man who solicited her for sex, must serve 51 years in prison before being eligible for release.

The five-justice court said Brown and other defendants who have been convicted of first-degree murder after July 1,1995, and then sentenced to life in prison can’t become eligible for release until they serve more than five decades in prison, CNN reported.

ADVERTISEMENT

Brown’s case last year caught the attention of high profile Hollywood stars, including Rihanna and Kim Kardashian, who used their social media platforms to protest the life sentence Brown was handed.

Brown said she shot and killed her victim, 43-year-old Johnny Mitchell Allan, after she resisted his advances, and after she believed he was reaching for a gun. She then took a gun out of her purse and shot and killed Allan.

A MoveOn.org petition has received more than 500,000 electronic signatures from people who support her release.

The unanimous ruling against Brown, who was sentenced to life in prison in 2004, followed a lawsuit in which she argued that her sentence was unconstitutional.

Brown had pointed to a 2012 Supreme Court opinion from the U.S. Supreme Court to argue in the suit that being sentenced to life in prison without the possibility of parole for juvenile offenders violated the Constitution.

The court denying the motion said she hadn’t received a life sentence without parole and was just handed a life sentence instead.

In a statement seen by CNN, the Tennessee Supreme Court explained 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,” which can reportedly be earned by actions such as participating in educational or career training programs.

The 6th Circuit Court of Appeals is reportedly pending judgment on the case and asked the Tennessee Supreme Court to share its own opinion.