Could you talk to the professor in charge of your real first choice (the general crim defense one) and feel him out, see what he's looking for, how many students he thinks will be selected, is any preference given to 3Ls over 2Ls, etc. This way, you can get a little more info, plus he'll know you're interested since you took the time to come in and chat, so when your resume shows up he'll likely remember your name.
It the professor makes it sound like you don't have much of a shot, like only accepting a couple 2Ls, only accepting GPAs at a certain level, whatever... then take the hint and just do the human trafficking one.