NASHVILLE, Tenn. — Tennessee's Board of Parole has scheduled a May 23 clemency hearing for Cyntoia Brown, who is serving life in prison for killing her customer when she was a 16-year-old prostitute.

Celebrities including Kim Kardashian and singer Rihanna have rallied support for Brown, whose lawyers say she was a sex-trafficking victim afraid for her life.

Prosecutors say she killed the man to rob him.

A federal appeals court, meanwhile, will hear oral arguments on June 14 to consider whether her sentence as a juvenile was so long it is unconstitutional.

Brown, now 30, was tried as an adult and convicted of first-degree murder. Her sentence required that she remain behind bars until she's at least 67 years old.