This is why a paranoid schizophrenic might become angry at someone watching videos on their phone on the bus. The listener believes himself to be doing a perfectly normal and harmless activity, whereas the paranoid believes that the watcher is beaming mind control rays into the bus driver's skull to make the bus late.
Of late, cops have been acting more like the paranoid schizophrenic, assuming that everyone is carrying drugs or terrorist bombs, and that the cameras and camera-phones used to record them are actually deadly weapons. This makes them supremely unqualified to determine what is "reasonable".
When I drive my car to work, and see someone running along the sidewalk, I do not assume they are running away from me. They might be exercising. Or perhaps that person saw a bee and is allergic to bee stings. Maybe their wife will be occupied for the next hour and their mistress is 3 blocks away. I don't know. I don't really care.
I don't have any reasonable grounds to impute motive to the running. Even if I know that there is a bomb planted in the sidewalk near them, I cannot assume that they are running from the bomb, because I cannot know that they know what I know.
If any reasonable person could conceive a plausible and probable reason for it, the behavior is simply not suspicious. And as a reasonable person, I might assume that people would run from the police in my municipality because they don't want to be confronted without cause, thrown to the ground, and hospitalized for spinal injuries causing paralysis shortly thereafter. It's simpler elsewhere; they just don't want to get shot, robbed (forfeiture), or even just have hours of their time wasted by police.
And you can't lower the standard when a crime is committed, because there is no magic mobile alert that goes out to everyone in the area whenever that happens. I have no way of knowing what external circumstances are in play that may make what I am doing right now seem more suspicious. The police can't beam their paranoia into other people's heads.
We can, and should, make their job harder, and demand higher standards of professionalism from them, right along with removing all the incentives for them to do their work in a lazy and slipshod manner. What they do now is currently so not-difficult that police departments can reject applicants who are too smart for the job.[0] The common functions that people actually want them to perform are also routinely handled by Brink's, Pinkerton, ADT, KBR, Chubb, Booz Allen, Securitas, etc., without any abuse of authority, because they have no more authority than their customers.
I'll respect what police do when what they do shows respect for the public, rather than unreasonable suspicion and violent hostility, with a nasty habit of looking the other way when one's co-workers do wrong.
[0] http://www.slate.com/blogs/moneybox/2013/05/01/too_smart_to_... http://abcnews.go.com/US/court-oks-barring-high-iqs-cops/sto...