If you really thought that they were terrorists, murderers, rapists, etc... you wouldn't try to stop them on the border any more than you would go into the inner city gang areas at night and try to take pictures of criminals committing crimes.
I see that you're still coming to the defense of your illegal alien lawbreaker buddies.
He and his pals rely on exploiting their cheap labor and no benefits. Cutting off the illegal aliens threatens his bottome line.