Hacked my cam to aid in committing a crime... police report made. HOW DID THIS HAPPEN?

Hi. I have a ring peephole cam on my apartment door. It's been extremely helpful recording crimes that have occurred; the most recent a few weeks ago. What I want to know is how can someone hack into my cam? What we can tell from my video feeds is that a woman repeatedly walked back and forth in front of my cam about 6-8 times, holding her phone and watching it and in some shots, you can see she is watching herself! On my cam! less than 12 hours after that, her roommate committed a crime at my door but hid herself behind a box so you cant see her face which means the police could not prove it was her - though we know it is. A few days ago, similar thing happened. Two guys repeatedly walked back and forth in front of my cam and also watching themseves on my feed. HOW? How can I secure this cam if at all?