I see that the Marines are being told they can "detain" people while waiting for police to arrive to "arrest" them.
I would mention that our very own SCOTUS says that if a person is not free to leave then that person is under arrest and must be given a Miranda warning.
Now --- here we have the Army or Marines "detaining" people - people who are not free to leave - and probably not giving Miranda warnings.
As such, were I the defense counsel, I would move for exclusion of all evidence gathered post "detention" as inadmissible because of lack of Miranda warning.
Police, ill as they sometimes are, are trained and often quite skilled in the obligations imposed by our Fourth Amendment. Marines are not.