Brothers Swae Lee and Slim Jxmmi make up Rae Sremmurd.

Their half-brother Michael Brown has become famous for a different reason:  He's been charged with killing 62-year-old Floyd Sullivan, who was a stepdad to Swae, Slim and Michael.

Brown, then 19, shot Sullivan to death on January 6, 2020.  Brown's mother Bernadette Walker says he suffers from Schizoaffective disorder believes he was off his meds when he killed her husband.

This week, Brown was charged with first-degree murder in the state of Mississippi.  It won't be tried as a death penalty case, but he will face life in prison.

Rae Sremmurd hasn't commented on the case.