As an ex-law enforcement officer myself, I would like to post two points:
First, on the "Use of Force Continuum", the mere presence of a law enforcement officer(either in uniform, or in "plain", "street" clothes, which includes essentially everything from t-shit and blue jeans, to issued polo shirt(usually with an embroidered badge, agency name, and officer's name) and approved pants(khaki, darker, or black pants or cargo pants), and including business casual(yes, polo shirts fit that definition in some working environments, but such terms are rather ambiguous) to business formal(suit and ties, and similar)) is the first level of said "Continuum". I can say, from my own experience, that many people feel intimidated by simply seeing law enforcement nearby that they have acted rather ridiculously, even when they were committing no acts that gave me authority to engage said people in an "official capacity".
I also witnessed quite a few people that, while attempting to effect a vehicle stop(after witnessing a moving violation upon a public roadway), people would attempt to "flee and elude"(part of the title of the Title 40 law(O.C.G.A 40-6-395) that covers people attempting to run from a legal stop, in the O.C.G.A., or Official Code of Georgia Annotated), "rabbit", or "run" from me, and after I finally got them stopped, or they stopped of their own desire(I am talking about people that were aware that I had been attempting to stop them, not people who didn't notice, but stopped the moment they did notice...situational awareness people!), I discovered they had no previous convictions, many times no previous citations, no warrants, etc. Said stops were for relatively minor issues, that ballooned into potentially major legal trouble(depending on the circumstances).
Secondly, law enforcement, at least in the United States, has no extra power to "kill or imprison" others compared to each individual citizen. One of the very few differences is that law enforcement can arrest on, and execute warrants(arrest and/or search), and, at least in the State of Georgia, and many other states, can act on traffic violations(up to and including arrests, depending), where citizen's witnessing traffic violations doesn't give law enforcement authority to initiate a traffic stop, or effect an arrest, unless a violation occurs in the presence of a certified and sworn(i.e. employed) law enforcement officer. Law enforcement officers are allowed to use deadly force to defend themselves or a third-party from greatly bodily harm and/or death(imminent death isn't necessary for deadly force, which it shouldn't be), or to stop a "forcible felony"(rape, armed robbery, kidnapping, murder, etc), and to also to stop an escaping, or escaped inmate that has been charged, tried, and convicted(though, reasonably, if lesser force will cease an escapee, or attempted escapee, that force should be used); a fleeing felon(not-yet-convicted, mind you) that doesn't pose a real and obvious danger to another people doesn't provide authority to use "deadly force". Nevertheless, law enforcement, regardless of the public view(which is wrong), doesn't actually have a "monopoly on violence". Citizens have the right to use force to defend themselves and others, where a law enforcement officer takes his or her right to use said force, as just another citizen, and applies to in the course of his or her official duties.
Remember, citizens are the only ones that have rights(...and rights aren't given by government, right are inherent; though, some explicit rights are protect, not created, by certain documents, such as the US Constitution, and/or the various state constitutions, and in through other avenues). Governments, the representatives of said governments, and the employees of said governments, only have limited authority to act in certain circumstances(in their official capacity; as fellow citizens, they have the rights that the rest of the citizen of the United States, and the various states, possess). The citizenry(I am talking about the United States alone; I don't focus on the strange ways of foreign governments) possess numerous and wide rights, some that were explicitly enumerated, many that weren't. Never equate government, on any level(within the United States, or the various states) as having any rights; it doesn't. ...but, I digress...
I will add that I have been rather unhappy with the way it seem law enforcement has changed just over the past 5 to 7 years alone. Though, it's important to look past the constant media focus on specific cases on any subject, I am talking more about the relatively recent case law, other judicial decisions, newer tactics, etc. Much of that is lessening my view of the profession overall.