Indictments rare, but police do get charged over use of deadly force

At least 400 people are killed by police in the United States every year, but even when those deaths prompt public outrage, grand juries almost always decide that the officer hasn't committed a crime.

But there are exceptions.

Successful prosecutions generally involve officers who have lied about what they've done, used excessive force to inflict punishment, or instigated confrontations for personal reasons.

Federal and state prosecutors have won convictions in several states.

This year, several officers faced criminal charges in North and South Carolina over fatal shootings.

Experts say jurors are willing to give the benefit of the doubt to officers who use deadly force on the job.

But that sympathy goes away if there is evidence that officers are using violence for retribution.