The Stephane's translation are perfect litterally : the 2 firsts sound a little bit too much "BPRD" to me, though the expression "cabinet des affaires" is typical of this time.
As option, may I suggest :
La Brigade mobile speciale (BMS)
The BMS is the idea of a Chtulu RPG fan :
http://www.brigademobile.org/It's very accurate historicallly, cause he was inspired by the real "Brigades mobiles" created in 1907 by Georges Clemenceau, aka le Tigre, so they were nicknamed "Les brigades du Tigre" (Tigre's brigades).
They were the first french unit of real Police (the Gendarmes belong to military corps) as answer to the violent expansion of Apaches and anarchists, and the first to use cars (hence "mobile")
The addition of "special" give it his
pulpish feeling, but you could make your own as :
La Brigade mobile des affaires occultes (BMAO)
La Brigade mobile des affaires paranormales (BMAP)
or for better acronyms :
Le Cabinet des affaires occultes (CAO as CIA !!! :mrgreen: )
Sorry for all this F words, the subject over-enjoyed me :roll: and for the names list, I'm going to look for.
meow,
Matt