@ossobuco,
Whilst your looking at this, please take my advice and get a chain or clip lock for your door, for when you are indoors. (clip locks are superior).
I have experience in locksmithing and slight experience in criminal behaviours and with some easily acquired tools, I can be in your home in less than 3 minutes silently, if you do not have a top deadlock or the above on your door. You should have the same security on second and third floor rear porches, it takes seconds for free runners such as my younger self to climb up and minutes at most for the older. (that is with joint damage too, do not underestimate the human ability to spurt a temporary juvenile phase over minutes).
The top deadlock is breachable too, so make sure you are safe inside.
On a less important note, if you are dealing with online stalking and suspect your keys are missing, use a local hardware store or locksmith, not eBay to get cheap replacement locks.. Some of the keys are quite often very basic and the locks have few levers. (but do not quote me on all sellers products please).
Dav.