We were talking about border towns with paramilitary assailants, that is something that is absolutely under the military purview.
Police is not trained, or responsible enough to handle military grade weapons. An argument could be made to give them access to military grade body west, but not for weapons.
That such a scenario is common enough, where civilians are committing crimes with heavy weaponry, is something that should be handled at the root of the issue. Not fighting fire with fire.