Minor Quibble:
He was charged a long time, then was an Article 32 hearing, with a referral to the Convening Authority (the infamous "Cut the kid a break" recommendation).
The Convening Authority (FORSCOM Commander) did the smart thing and kicked it to a Courts Martial.
Not sure how the CA will pick the officers/NCO's to be on the jury, but when I was in, there was a duty roster. Other than MP's and JAG's being permanently excused, the only way to avoid the duty was that it was one of your soldiers on trial.