Exactly right. I will to do what I can to help the police catch scammers and crooks who want to steal from people. The police might use those same tools and techniques to help catch people who use bitcoin to pay for drugs; I can't stop them from doing that.
Are you saying you would want to work on "coin un-mixers", software that attempts to reduce the effectiveness of coin mixers? (Using statistical analyses on the public data of the block chain.)