Who's the Peepin' Tom?

So Jay's been staying at work for the past few nights, and Erin gets a little scared at night, all alone in the Alley. Last night at around 2:40 a.m., someone showed up knocking on Unit B's door forcefully. I thought I was imagining things, but Abe was freaking out and ran to the door. I got a stool so I could see through the peep hole (I'm too short), but there was no one there. Umm, okay... scary. I call Jay, he says it's probably Dave looking for cigarettes. I was too scared to open the door, so I just went back to bed. At 3:00 I'm laying there, and I'm still freaked out, and I'm looking at the windows... and I see someone's head peeking in our middle window. I just freeze, I don't know who this is, it's 3:00 a.m. and I really must be lonely... and freaked out! They walk over to the door and knock again, five times pretty loud... I scurry over to the door, the stool is already set so I can climb on up, and there's NO ONE THERE. I just got so freaked out, I don't know who would knock and not wait for an answer, no less peek inside at 3:00 a.m. So I called the cops, and I told them what happened. They sent someone out, but they sent them to the FRONT door. So I'm standing there, shaking while balancing on the stool and looking out the peephole, and I hear "WEEEOOOooooOOOOOPppppEEEEE!!" (That's our door buzzer.) I scurry to find my keys, I don't want to go outside... scary! "WEEEOOoooOOOOoppPPPPPPEEEeeeoop" again... I run out, talk to the cops, tell them what happened. They said they've gotten some calls of a Peeping Tom lately in this area. Great! I forgot to ask them why the hell would he have knocked?? So maybe it WAS Dave, or some person who was at an Alley party, or something... but I was freaked out anyway. Poor Jay, he drove all the way home at 3:30 a.m. to keep me company 'cuz I was scared... thank you, sweetie! So watch out, don't sleep naked (that especially goes for ground-floor Steve!).