Background: Teenager breaks into home, steals woman's purse, she calls police. Police show up in time to chase teenager with purse. This crime is a felony in Tennessee at the time. Kid tries to hop fence, cop shoots kid in the head in accordance with TN state law regarding fleeing felons. The officers involved were cleared because they were following the law. Family files complaints, goes all the way to the SCOTUS. The SCOTUS find that use of deadly force must be justified by either an immediate threat of serious harm or the expectation of the suspect harming someone else in the future.
When all the facts are considered in this case, that is the legal standard the officer will have to satisfy to avoid being found guilty.
Now since he has been fired by his department, all of that will be on his own dime. He better have some healthy liability insurance.
If the officer is exonerated, he should and will sue the Department for termination and hopefully, attorney fees. The Department appears to be was waaay too hasty in its decision.