My prior job was working for the state in civil actions - that means I was defending the state from people who were suing it or its employees for money damages. So no, I couldn't refuse to take cases. But even if I could have, I wouldn't have.

Most of defense law isn't about getting "guilty" people off scottfree. It's much more about defending your client's rights and ensuring that our system of justice works well for everyone. In a criminal case that means that you make sure that the state attorney can prove their case beyond a reasonable doubt. If they can, then the "guilty" person is rarely going to get off. If the state can't prove that burden then that person should not be criminally punished.

Even in this case, it is pretty obvious that both sides of the story aren't being portrayed. The guy who got pepper sprayed was very likely going absolutely ape-shit. Controlling someone who is going absolutely ape-shit is not a real easy job. My job as a defense lawyer, if there was a viable defense, would be to make sure that the jury got to understand the whole story and not just the side saying "look they killed an innocent person!"