How many

[gandalf91]

If my memory serves me correctly, 6. *Excluding this: http://www.frictionalgames.com/forum/thread-7657.html

Other than those, there is a scene where a Brute(If I remember right) is seen walking past a doorway at the far end of a hall that freaks you out, but I don't think he ever strays from that.

I don't recall any glimpses of the brute in the northern section, but there are two in the south section.

Spoiler below!

The first is behind a locked door at the end of the hallway if you hang a left before the first ascending staircase. A man gets slammed against the door, killed, and then the brute walks in the other direction which you can see through the vented opening in the door. The next one occurs if you hang a left at the far end and approach the door that separates the north and south blocks that is locked. (With the lock in "excellent condition".) It walks across the hallway towards where the kitchen is located on the next level.