Cops don't want to shoot innocent people. They want to do their job and get home safely. But last year, 62 cops were murdered while on duty.[1] Even more were shot and survived. For cops, every traffic stop is a second away from becoming deadly. They don't know if the person they pulled over is armed or crazy. Looking away for a moment can get them killed. Don't believe me? Watch this cop's body cam.[2] Now imagine seeing similar videos every few days, because that's how often it happens. You don't think you'd be on-edge?
While police work isn't particularly dangerous compared to fishing or logging, people can't internalize that fact. And in fairness to intuitions, much of the risk is compressed into short moments such as traffic stops.
Are some cops sociopaths? Yes. Should every cop have a body cam? Yes. Do I think most police departments have problems with excessive force, discrimination, and hostility? Definitely. But it makes no sense to demonize people who, at the end of the day, just want to see their family.
One more thing: I'm very glad the Sandra Bland video was released, as it is a perfect example of a cop behaving horribly. Hopefully, more bad cops will get the message: if you act this way, you will be discovered.
1. http://www.nleomf.org/assets/pdfs/reports/Preliminary-2014-O...
2. https://www.youtube.com/watch?v=O8-hgt8Z_qI&t=27 (warning: loud & graphic)
Edit: Apparently, this topic is poison to rational discourse. Please remember the principle of charity and avoid nitpicking or misconstruing.