I’m a little rusty on the UCMJ, but in my day, we would have charge Hasan with the following Articles:
80 – Attempts – as attempted murder, 31 counts
81 – Conspiracy – for contacting radicals prior to the act
89 – Disrespect toward Superior Commissioned Officer – for any senior officer that may have been in the line of fire
90 – Assault on a Superior Commissioned Officer – for any senior officer that may have been in the line of fire
92 – Failure to obey a lawful order – for failing to stop when ordered to do so
93 – Cruelty – both mental and physical, one count for everyone present at the time of the attack
94 – Mutiny – Fairly obvious
95 – Resisting arrest – had to be shot to get him to stop
104 – Aiding the Enemy – includes any contact or communication with the enemy, one count for each conversation
106 – Espionage – ditto above
108 – Damage of Military property – one count for every service member shot, plus buildings and any other damage done
116 – Riot or breech of peace – For the chaos at the shooting scene
117 – Provoking speech or gestures – ALAHU AKBAR before & during the shooting
118 – Murder – 13 counts
124 – Maiming – 54 counts
128 – Assault – 54 counts (plus additional counts for anyone present even if they weren’t shot)
133 – Conduct unbecoming an officer and a gentleman – Fairly obvious
134 – General Article – For action not condusive to good order and discipline

He should be convicted by a General Court Martial on all counts, then hung.