as I understand it, the purpose of Posse Comitatus is to Prevent the military being used against citizens. I would surmise that an illegal is fair game for any military branch...technically speaking, of course.
Prevention of using the military to enforce domestic laws, and yes, against citizens. However citizens don't have a tag on their foreheads IDing them as such, so the use of the Natl Guard is preeminent. Having been in the situation, it is sad to see the way the US military has to bend over backwards to prevent offending an illegal because of 'posse comitatus' because you have no way of knowing for sure who the sob is.
The time may be close for POTUS to do what is essential and challenge the den of carpetbaggers to impeach - or shut up! {+ MSM} These globalist traitors need to be taken head on.
An illegal that is a murderer, a rapist, MS13, narco mule... they have been careful not to attack with guns and such, but Border Patrol is ill equipped to repel hundreds of rock throwing attackers, especially at multiple border points simultaneously.
Of course my plan has been posted a few times, and I have sent it to the WH; it is a plan that can only be carried out by the military:
MINE THE BORDER!