It's a tough call. I don't like police being on campus yet it
  enforces accountability for the whole population, students,
  teachers and administrators... theoretically. But there's
  abuses. We have cops on campuses here but their role seems to be
  that of "Here's a friendly cop", an attempt to make the police
  less scary and have an outside authority to turn to if there's a
  problem. But... I dunno. To me, it's like they just gave up on
  pretending that school wasn't a prison and just said, "Hey
  everybody, yeah, not only is our current architectural designs
  make modern schools look like prisons, but HEY! Here's the
  prison guards! Have fun for 12 years....