I've never seen so many people in so many operations so unhappy. Cops get hired out of our flawed, human population. The process screens out numerous applicants for every one who makes it through. Still, things go wrong, break down, fail to work, or people fail to communicate. Because of low pay compared to the private sector, many talented people never go into law enforcement, especially given its constraints and comparatively sluggish upward mobility.
People die in car accidents.
From time to time, cops act illegally, corruptly, brutally. By all means, we must stay vigilant, and weed them out. But let's have perspective. Cops live real lives. They make mistakes.