Charges in instances of prison riots

When a riot occurs in prison, the inmates sometimes seize a guard or other prison employee and hold that person during the period of the riot. Not all the inmates will directly participate in seizing or holding the guard, even if they otherwise participate in the riot.

When the riot is quelled, what charges can be brought against the inmates? 

What should the government have to prove to convict an inmate of these charges?

See Comm. v. Spearin, 846 N.E.2d 390 (Mass. 2006).”