I couldn't think of the name of this law before, so I couldn't look it up. So I asked my husband why it was that Navy ships couldn't stop drug boats without the coast guard being on board. He said, "It's Posse Comitatus, baby." I think this may clear up a little bit about why the military is limited in investigating this murder that occurred off the base or why they didn't get access to Maria's cell phone records and whatnot.
The
Posse Comitatus Act . . . prohibits most members of the federal uniformed services . . . from exercising nominally state law enforcement police or peace officer powers that maintain "law and order" on non-federal property.
The statute generally prohibits federal military personnel .. . from acting in a law enforcement capacity within the United States, except where expressly authorized by the Constitution or Congress. The
Coast Guard is exempt from the Posse Comitatus Act.
The Posse Comitatus Act and the
Insurrection Act substantially limit the powers of the federal government to use the military for law enforcement.
http://en.wikipedia.org/wiki/Posse_Comitatus_Act
Anyway, that's what I was trying to get at before.