These people don’t want justice they want murder because they are hateful. Just look at the faces of evil.
If the police officer is charged, the crowd still won't be satisfied, so they'll protest and use it as an excuse to get violent. The problem then would be that people who care about law and order will also be disgusted. It could get weird.
I honestly don't think that if I were a police officer I would do anything to put myself in harms way if there's anything but a "not guilty" decision. JMHO