Indiana Code Title 10. Public Safety § 10-16-8-12

Sec. 12. (a) If the Indiana guard reserve or any part of the Indiana guard reserve is requested to provide voluntary service, the members of the Indiana guard reserve shall follow the orders and guidance of the Indiana national guard's chain of command and the rules and regulations adopted by the adjutant general under section 2 of this chapter regarding the discipline of members of the Indiana guard reserve.

(b) A volunteer responding to a call to voluntary service with the Indiana guard reserve may not be arrested on any warrant, except for treason or felony, while going to, remaining at, or returning from a place where requested to attend for voluntary service with the state. A volunteer of the Indiana guard reserve is, during the service in the Indiana guard reserve, exempt from service upon any posse comitatus.