Can we trust the police? (USA)
"Bad apples" will always exist, but the problem is when police departments cover up for them, or no action is taken when they are proven to have lied about misconduct.
Some perspective when considering police use of deadly force: US annual fatal shootings by police: ~1000 US annual deaths caused by medical error: ~250,000
Implicit racial bias affects many of us, regardless of our own race. The decisions police make are usually in favor of white people - even black police, and those who sincerely believe themselves not to be racist.
On the whole, cops are more professional, better educated and better trained than ever in history.