I'm not so sure. TrueCrypt is first and foremost an encryption program. The fact that you have it might suggest that you encrypted something somewhere, but it doesn't directly suggest that you took the time to use its advanced "hidden volume" capabilities. So even if the police can say "hey, this looks encrypted, and you've got nothing else which looks similar, decrypt it for us," they are still stuck on "hey, we didn't find the evidence we were looking for -- maybe you have a hidden volume?". You say "I don't" and the judge says "GRR ARG DECRYPT IT NOW" and you say "I can't, it doesn't exist, I really am innocent, please get the scary men away from me."