Associate opponent charges with old news. A derivative of the straw man usually, in any large-scale matter of high visibility, someone will make charges early on which can be or were already easily dealt with. Where it can be foreseen, have your own side raise a straw man issue and have it dealt with early on as part of the initial contingency plans. Establish and rely upon fall-back positions. Others can reinforce this on your behalf, later.
Enigmas have no solution.
Drawing upon the overall umbrella of events surrounding the crime and the multitude of players and events, paint the entire affair as too complex to solve. This causes those otherwise following the matter to begin to loose interest more quickly without having to address the actual issues. Alice in Wonderland Logic. Avoid discussion of the issues by reasoning backwards with an apparent deductive logic in a way that forbears any actual material fact. Demand complete solutions.