Every job you mentioned does in fact have it's own dangers, but every police officer knows, that each and every day there are those that would, if the chance arise, do everything in their power to prevent a police officer from detaining them, none of the others go to work daily with the knowledge that a fellow citizen will, if given the chance, kill them.

  None of the other professions leave for work knowing they are a target for those that pose a threat to society, while some, such as yourself, prefer to cast undue slanders against them, but they would still come to your defense if necessary, asking nothing in return, but simple respect.