Justin Johnson is accused of being one of the two men who pumped 22 bullets into Young Dolph as the rapper shopped for sweets at Makeda’s Homemade Butter Cookies in his hometown of Memphis on November 17.
The 23-year was hit with first-degree murder, theft, and gun charges in Dolph's homicide and is currently locked up in Tennessee's Shelby County Jail.
On Friday, Johnson was attacked by another inmate as he made a phone call.
According to his lawyer, he wasn't severely injured.
The lawyer didn't know the motivation for the attack.
In addition to allegedly killing Dolph (Johnson maintains he's innocent), Johnson has served time for a bowling alley shooting and is on the sex offenders registry for an aggravated rape charge.