OK, let’s go! I measured a blow up of the pic, and measured the uncut base and each cut position in inches. Then I took the measurement for the uncut base and divided it by .315”, the measurement of the uncut Schlage base. This gave me a ratio that I could use to determine the actual cut depth from there depths measured in the photo. I then looked the cut depth cut number by cut depth, and lo and behold, your friend has a Schlage key cut to 5-4-4-8-5. So you know everyone that knows your friend’s reddit name to be trustworthy? Rekey the lock. The problem you bring up does not recognize the two types of unauthorized entry, those that leave evidence and those that do not. If someone can slip into your friends house many times, undetected, and over a long period of time, well that’s very different from tossing a brick through the window. Rekey the lock.