For the record, there is nifty activity monitor. You’ll get instant notifications on who’s been in and out. And if you really feel like it, you’ll be able to go back in time with the history log.
See who comes and goes with the Activity Feed. Check who unlocked the door and if or when it was actually opened. Set-up alerts to notify when specific people arrive home. Check to make sure your visiting friend got in, how long the cleaner was there, or see who’s been inside if you suspect unusual activity.