I'm sorry for what you're having to deal with Sunflower, that sounds terrifying. I would definitely let the police know.

I remember when I was a teenager at one point at my house we had some very creepy phone calls come through several days in a row from someone and some banging on our downstairs sliding glass door. Eventually we had the police come over to search the property, never figured out who it was. But whoever they were they stopped after that

I hope you're able to get it resolved so you don't have to deal with that anymore