The security guard alleged to have killed the rapper Proof in a nightclub in Detroit will not face any additional charges over the shootout.
Mario Etheridge could be sentenced to several years in jail if convicted
Mario Etheridge acted within the law, prosecutors say, because he was trying to defend his cousin, Keith Bender.
Mr Bender was allegedly shot dead at the CCC club by Proof, a member of the group D12 and a close friend of Eminem.
Charges of carrying a concealed weapon and unlawfully firing a gun still stand against Mr Etheridge.
Mr Etheridge fired twice at the ceiling to try to stop Proof before aiming the gun at him, Wayne County Prosecutor Kym Worthy stated.
"The evidence clearly shows that Mario Etheridge acted in lawful self-defence of another when he shot Deshaun Holton," she added, using Proof's legal name.
The dead rapper's estate is being sued for wrongful death by Mr Bender's wife Jacqueline and mother Leona.
At Proof's funeral, Eminem said the rapper was "a people magnet"
They claim Proof "violently assaulted and battered" Mr Bender, before firing the shot which killed him.
However, Proof's lawyer, David Gorosh, said "conflicting eyewitness testimony and an inconclusive ballistics test" had "left unanswered questions" about the shooting on 11 April.
"We will have the bullets from the crime scene examined by an independent ballistics expert in the hopes of putting these questions to rest in a final, thorough and conclusive manner," he said.
"I believe that these independent findings will motivate the Wayne County Prosecutor's Office to re-evaluate its position."
Mr Etheridge's lawyer, Randall Upshaw, has countered that a drunken Proof became aggressive during a game of pool.
Prosecutor Kym Worthy said there was "clear evidence" of self-defence
He claimed Proof argued with Mr Bender and later returned with a gun, beating him with the weapon before shooting him in the face.
Mr Etheridge's final pre-trial court appearance is scheduled for 2 June.
If convicted, he faces a maximum of five years in prison on the concealed weapon charge and four years for discharging a firearm.