Mystery weasel

At about 10:30 this evening, walking home from returning the rented DVDs, I spotted what I thought was a big grey cat slinking up the stairs at the apartment building next to ours.
Only it wasn’t a cat at all. But I don’t know what it was. I’ve been searching on the ‘net to no avail. It’s not a weasel/stoat, tanuki, raccoon, or ferret, as far as I can tell. It might have been a Japanese badger, but from the photos I’ve found, the tail is different…can anyone identify this animal? I didn’t have my camera with me (drat!) but here’s a description:
length: approx 1 meter (including tail)
legs: short, black, no defined joints or hips
tail: pretty bushy, grey with black at end. length is about as long as the body
fur: sort of fluffy, grey/brown with black legs, tail end. lighter markings on ears and top of head
ears: small, pointy, dark
head: about as wide as body, triangular, whitish stripe down the middle towards nose
What the heck is a wild animal doing in my paved-over neighborhood??