The stereotype is probably if anything less horrible than the reality. There was a notable situation where police were called because 12 year old Tamir Rice was walking whilst black with a bb gun. The officer exited the passenger side of the cop car so fast it was still moving when he jumped out. He immediately fired and executed the little kid. Despite the horror of the situation this is what would be colloquially termed a "good shoot" and officers faced no legal consequences.

Despite officer being 25th on the list of most dangerous professions falling below construction helper and farmer officers are trained as if they are going to war and equipped with many of the same toys. They are taught to prioritize preserving their lives over those they are supposed to protect.