Who killed the drugstore owner in the novel Monster by Walter Dean Myers?

In the novel Monster, Richard "Bobo" Evans testifies that James King shot and killed Aguinaldo Nesbitt.Bobo tells Petrocelli that King smoked some "crank" before they entered the store. Upon entering the store, King began arguing with the store owner while Bobo reached for the money in the cash register. Bobo says that he heard a shot and turned around to see King holding a gun. After the robbery, Bobo said that he asked...

In the novel Monster, Richard "Bobo" Evans testifies that James King shot and killed Aguinaldo Nesbitt. Bobo tells Petrocelli that King smoked some "crank" before they entered the store. Upon entering the store, King began arguing with the store owner while Bobo reached for the money in the cash register. Bobo says that he heard a shot and turned around to see King holding a gun. After the robbery, Bobo said that he asked King what happened, and King told him that the store owner tried to "muscle him." When Asa Briggs cross-examines Bobo, Bobo tells Briggs that the reason King shot the store owner was because he was high.

The detectives were not able to retrieve any fingerprints from the scene of the crime and the gun legally belonged to Nesbitt. Myers does not clearly state that James King pulled the trigger, which makes the question of who killed Nesbitt ambiguous. However, the jury ends up finding James King guilty of felony murder and sentences him to 25 years to life in prison.