how do defense attorneys deal with the moral dilemma of representing people they know are guilty?

Answer 1

Follow Bob Pursley's link on the difference between Morals and Ethics in his response to "Ilisa" a little further down this list: it'll give you some help in at least defining the problem, if not some help answering it.

Answer 2

http://www.jiskha.com/display.cgi?id=1284869187

This is what David is referring to.