Billy Ray Turner of Tennessee accused of killing former NBA player Lorenzen Wright pleaded guilty on Monday to a separate charge.
Shelby County prosecutors said Turner illegally had two weapons in his possession when he was indicted in December 2017 for killing 34-year-old Wright.
Turner has already been convicted of dangerous endangerment by a deadly weapon.
Turner and Wright's ex-wife, Sherra Wright, conspired to kill the retired NBA player and Memphis native in July 2010, officials said.
The body of Lorenzen Wright was found riddled with gunfire in a swampy field of Memphis 10 days after his disappearance.
Turner and Sherra Wright pleaded not guilty to first degree murder.
Turner faces 12 to 20 years in prison for the July 26 firearms charge.