Authorities charged Karmbi Octavious Young, 20, in addition to three men and a juvenile in the shooting death of Rickey Gibson, 33, of Grovetown.
A Columbia County jury convicted Mr. Young last month of murder, armed robbery, burglary, kidnapping, two counts of aggravated assault, two counts of possession of a firearm during the commission of a crime and possession of marijuana.
Superior Court Judge James G. Blanchard Jr. sentenced Mr. Young to life in prison plus 70 years.
David Brunk, the defense attorney for Garland Ray Pittman, 15, filed an intent to seek the insanity defense, which required a mental evaluation to determine his competency to stand trial.
Dr. Adriene Davis, a state psychologist assigned to complete the evaluation, attempted the evaluation three times.
Each time Mr. Pittman was either uncooperative or unable to complete a thorough interview. She refused to provide a determination, saying that Mr. Pittman got easily frustrated, had an inability to communicate effectively and could not clearly explain the rules and procedures of the court or the roles of its officers.
"I think he generally gets confused," Dr. Davis said. "He struggles a lot to reiterate and explain issues relating to competency."
Mr. Brunk stated concerns about Mr. Pittman's ability to assist in his own defense.
Judge Blanchard ruled that Mr. Pittman was competent to stand trial.
Reach Valerie Rowell at (706) 868-1222, ext. 110 or firstname.lastname@example.org.