For a time I worked on a project dealing with the history of cavalry in the US Army, and got my first exposure to the Constabulary forces there. They were really a fascinating bunch, held to a higher standard than normal troops and given very precise instructions regarding the use (or non-use) of force to help maintain order. They were envisioned as an elite, and expected to conduct themselves as such. They were also formed in part to counteract the sliding discipline of many of the Army units in Germany who were (understandably) anxious to go home and demobilize.