A similar situation happened to me! DO NOT TOUCH ANYTHING Call the non emergency number! If they are annoyed that they came out and it winds up being garbage, who cares? At least you didn’t ignore something potentially very important.
In my case, it was a suitcase that had duct tape around it. That showed up overnight. I called local cops first that sent guys out that seemed bored, honestly. And my heart was racing as I answered questions. When they opened the bag, it had ripped clothes and a half used roll of duct tape. The local PD literally said “well, we don’t have a crime we can match this to.” They started to leave without the bag and I was confused why they wouldn’t at least take it for evidence? I have watched too many episodes of CSI, cold case etc and was freaking out. They left. I guess they just want to make money on traffic stops.
I couldn’t leave the situation there, and a friend knew someone in the State Police. After a few phone calls I got in touch with a detective. Who was very confused that the local cops had handled the situation like that. He arrived and took the bag into evidence and got my information. As far as I know, nothing ever came of it.