I am not really following the reasoning behind what some of you are saying. When someone becomes a police officer we expect them to deal with potentially dangerous situations without killing people. That is a part of the job, especially in high-crime areas. Whether the victim here did something stupid or not does not absolve the killer. I am not familiar enough with the legalities of Unintentional Manslaughter (legalities weren't part of the discussion here anyhow), but on the face of it this sounds like it fits the bill. Will all of those aspects mentioned be brought up in court as mitigating factors? If her attorney is worth anything then yes, but that doesn't change that she killed someone with no adequate justification.
We as a society gave cops and soldiers guns, training, and a list of rules to follow. Human made rules can never be perfect yet we still decided to hand them guns anyways, accepting the collateral damage to keep our society safe as a whole. We still should strive to learn from our mistakes and perfect the rules to our best capabilities.
If the court determines that the PO was not negligent and followed the rules, then she is not to blame for his death. The system is to blame, and the system is us. Don’t hate the player, hate the game.
If this PO was someone close to you, you would tell them to not live with guilt or feel guilty, and you’d fully believe it.