Thank you all for your responses.
I regretted posting this negative story on here.
When I called the police, the dispatcher asked me if she had dementia, to which I answered, No, she's just mean (which is true). I talked to two sets of neighbors about this incident, and they both stated emphatically that she has been this way for over 40 years (the entire time they've lived next to her). I do know that people with dementia can become mean (even meaner), but this is not the case here. Just an evil, toxic human being I have the misfortune of having as a neighbor.
Today, I will focus on more positive things.
Thanks again, PC friends!