Why He's Guilty: Ezra is clearly distraught, consumed by grief, and filled with anger. We don't know exactly where he was around the time Charlotte was killed. We know he explodes at the gang when they tried to talk to him about it. Plus, Ezra has been involved in mischievious activities before. Could he be picking up where he left off?
Why He's Innocent: While Ezra has been shady in the past, he never actually involved himself in the whole "A" ordeal. And he might be angry, but he'd absolutely be misplacing his rage if he took his frustration out on Charlotte. It seems more like poor timing. Plus, his nine iron golf club isn't even missing!