Mr. Wilkins, your original post ended with: these high profile cases would have different endings had the suspects cooperated.
Small but significant percentages have never cooperated, hence handcuffs and other "accessories"...and the extensive training that officers are (rightly) so proud of.
Law enforcement is uniquely dangerous and stressful and difficult, but nonetheless the people who do it chose it...and therefore chose the expectation of professionalism that comes with it. That professionalism and training is particularly important in the last few seconds...
Every time lapses in professionalism are seen, confidence erodes. Perhaps those who "have a biased opinion about law enforcement" are simply people who have experienced enough lapses...
These "lapses" are obviously going to be less hidden with the very rapid expansion in the number of cameras in the last few years. All public professionals must improve their behavior accordingly...sports (Ray Rice), politics (Anthony Weiner), etc.
As Supreme Court Justice Brandeis famously said: sunshine is the best disinfectant.