Prosecutors said they believe Burr fired the fatal shot.
"We believe based on his involvement in the other robberies, he was most likely the triggerman in the homicide. We don't know 100 percent for sure. It was Gabriel Edwards’ DNA that was found on the gun after it was tossed. But we think it was most likely because he tossed the gun," deputy prosecutor Jeremy Teipen said.
Edwards’ attorney said his client was led astray.
"This should send a message to everyone. Be careful who you hang out with. It's not important that you are the trigger person. You could be the person with the triggerperson and by hanging out with them, being with them you could be held equally responsible and that's exactly what happened today," Kenneth Riggins said.