rogues' gallery

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A collection of pictures of known and suspected criminals maintained in police files and used for making identifications.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A set of pictures of convicted or suspected criminals used in law enforcement investigations to help witnesses identify suspects.
• noun idiomatic, by extension A group of lawbreakers or other disreputable characters.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a coterie of undesirable people
• noun a collection of pictures of criminals