Thinking back to when it happened to me. Similar story: 11:30pm, the entire house was asleep when suddenly a loud banging starts reverberating throughout itas an officer is banging in the window, loudly repeating himself asking if any one is home. He starts shining his flashlight through all of the windows until my mother, brother, and I go to the door. None of us are properly awake and the experience is nerve racking as I had no idea what the reason for his visit was given that I hadn't checked the forums and heard of Ken's arrest. He says he is looking for me, and proceeds to loudly state to my family that I ordered a "Suicide Kit" just like what happened to you. Interpol, customer records etc. At that point I'm frozen and panicking as I've just been exposed in such a way. My mother starts exploding at me which is even more embarrassing with the officer in front of us, he asks me to provide the package and states that he needs to follow me. I retrieve it from my room and give it to him, he asks why it's opened and I tell him I performed a small test a while ago which he is not happy to hear. I'm informed that an ambulance is getting dispatched. I try to explain to him that I ordered months ago for peace of mind, but he is uninterested and we have to wait for the ambulance.
We end up sitting outside in the cold for 2 hours as it was a Saturday night and the ambulance kept communicating with him, telling him that they had urgent cases and ours was delayed. My mother and brother did not follow us outside as she was unable to control herself. I just sat there with my head between my knees and my heart racing the entire time. Eventually the ambulance arrive and they are kind albeit patronising in their questioning. I explain that I'm not in immediate danger and after a back and forth and the officer interjecting, they leave. They were very much trying to get me to go to a pysch ward but we settled on a compromise that i would go to the hospital the next morning, which I did not do. The neighbours motion sensor lights were going off repeatedly during those two hours so it was very clear they were eavesdropping. Overall a very upsetting experience and if anything made me want to CTB much more than I did previously.
It seemed a theme in these visits was the lack of knowledge on the subject by the officers, and their discourteousness. This reply is months late but I can across this thread and your story was similar so there you go.