Ronald Cosper is already facing life in prison.
In April, the 21-year-old was convicted of felony murder in the 2012 death of Steve Mosley. That charge carries an automatic life sentence, which Hamilton County Criminal Court Judge Barry Steelman pronounced just after the jury's verdict.
Cosper's trial also ended with a conviction on a count of attempt to commit especially aggravated robbery. Prosecutors said Cosper planned to rob Mosley, who he called "the Weed Man," but shot him to death when things went wrong.
On Monday, Cosper agreed to an additional 10-year sentence on that second charge. He was facing between 8 and 12 additional years. The 10-year term will be served at the same time as his life sentence.
Cosper's attorney, Andrew Basler, contended throughout his April trial there was no proof Cosper shot Mosley. Two other men were charged in connection with the crime, and Dustin Hayes testified that Cosper was the shooter. Devante Stoudemire pleaded guilty to a lesser charge in May and was sentenced to 15 years in prison.
Basler said Cosper already has filed a motion for a new trial and moved for post-conviction dismissal.