this WHOSE shit?!

So I’m sitting here at work and I get this e-mail from K:

DUDE. Someone took a monster SHIT outside our door this morning.

Blink.

Blink.

What the hell??

Okay, let’s examine the facts.

A) There are no dogs allowed in the complex.
B) We live on the second floor, away from the street, so the odds of someone walking their dog, only to have it run away and UP the stairs, stopping only to leave a deposit on our doorstep, are fairly remote.
C) K left around 6:45AM to take her boyfriend home, and the shit was not there.
D) I left for work around 7:15AM, and the shit was not there.

From these facts, I have come up with the following possibilities.

1) It was a particularly, er, productive cat. I consider this unlikely, as I’ve been around cats my entire life, as has K, and I don’t think either one of us has seen a mound of cat shit large enough to warrant comment. (Smell, however, is another story; cf. The Great Fettucini Incident of ’01.)
2) Someone in the complex has a forbidden dog. This scenario is more likely, although if this were the case, why would they be walking it in broad daylight, risking discovery and potential eviction?
3) An actual human being took the time and trouble to drop their pants and release their bounty of shit on OUR doorstep.

But who? Why? We haven’t been there long enough to make any enemies, and we’re about the best neighbors one could hope for anyway. Is it a case of mistaken identity? A Santeria ritual? A drunk?

Who?

Why?

Someone get me Hercule Poorot.