I strongly urge you to consult with an experienced personal injury attorney about this. If the man was inside of the forbidden zone set by the protective order with no reason, he should have been arrested. The issue is going to be was it foreseeable that the person under the order would return again later and injure your loved one, and it would appear the answer is yes.
The Optional Information and Already Tried sections of the post are not showing on the screen at the moment, so I do not know where you are, but if you are in a smaller area, consider going to see an attorney in the nearest larger city. As you know, in a smaller town, everyone knows everyone, and a local attorney may not want to take on the police department because the attorney has to deal with them on so many other matters, and may have friends on the force. Also, in some cities there are attorneys who specialize in suing governmental agencies, including law enforcement, and it would be worthwhile to see if one of those is near you.
Also, if you are turned down by the first lawyer with whom you speak, consult with another, as this is the type case where lawyers can reasonably disagree on the validity and strength of the case.
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