Lurking in shadows and coming up a blindspot. My complex isn’t gated; now I know when I go outside, I’m heavy.
Also carry a very powerful tactical light. At night, pistol in right hand, light in left hand held with the beam-end past your little finger. As the pistol goes out in your right hand, your flashlight goes up in your left hand to just off your left shoulder, aiming forward. The beam is in in front of you and just off to the left. It will blind the bad guys, positively ID them, and the side-shine will illuminate your sights. You can shoot at night just like day this way, even if it’s one-handed. Or you can put a light on a rail on the pistol, but then it’s harder to holster, and the light is in line with your body. Either way, a tactical light should go with you at night anytime you carry a pistol. Just IMHO.
Another idea that may have its uses: once you are carrying a super bright tactical light in your left pocket all the time, you can take it out anytime you like, it’s just a light, about 6” by 1” diameter. See some dark areas up a 100’? Light it up. Cockroaches hate the light. They thing the cops are out patrolling. It makes them fade. Or it shows them at a distance that works for you and not for them. All they see is the bright light, they can’t see you. You could be a pair of cops. They don’t like lights, and there is no law against shining bright lights into dark places at night.
Knowing your neighborhood there is a very good chance they were on foot and likely to be somewhat local to you.
I can bring over a few bear traps if ya like.