I contacted the Law Enforcement Alliance of America and this is what I got from them:
Ray,
You've hit on one of the biggest unknowns in HR 218. There are a lot of problems with implementation that will likely require some court rulings or agency findings in order to sort out. As far as the military goes, it is unclear. So far, most of the legal counsel who have reviewed the statues feel that likely MP's may not be recognized, but perhaps criminal investigators, CID, NCIS might. The dilemma involves the posse comitatus separations of power between the military and domestic law enforcement.
My understanding is that military police and CID staff are empowered by US code and UCMJ to enforce UCMJ provisions and regulations. There is a grey area though in which those same military personnel can make arrests for violations of state ordinances on post for offenses such as drunk driving, etc.
The attorneys I have worked with have all said that they could not comfortably tell a client who is a military law enforcement officer that the provisions will cover them and they would be immune to prosecution based on the protections of HR 218. But even regular officers are facing areas where the arresting officials and prosecutors do not fully comprehend the protections granted to qualified individuals carrying under the statute.
LEAA supports the idea of allowing military law enforcement to be included, as we are fighting for the broadest possible interpretation.
I am sorry I am unable to provide any clear and solid answer to your
question.
-Kevin
Kevin H. Watson
Communications Director
Law Enforcement Alliance of America
www.leaa.org