In practice, the problem of law enforcement is half a matter of what the government does to catch violators and half a matter of what violators do to avoid getting caught. In the theory of law enforcement, however, although the state’s efforts at “detection” play a decisive role, offenders’ efforts at “detection avoidance” are largely ignored. Always problematic, this imbalance has become critical in recent years as episodes of corporate misconduct spur new interest in punishing process crimes like obstruction of justice and perjury. This Article adds detection avoidance to the existing theoretical frame with an eye toward informing the current policy debate. The exercise leads to several conclusions. First, despite recent efforts to strengthen laws governing obstruction and perjury, sanctioning is relatively inefficacious at discouraging detection avoidance. Sanctions send a mixed message to the offender: Do less to avoid detection, but to the extent you still do something, do more to avoid detection of your detection avoidance. The Article argues that detection avoidance is often more effectively deterred through the structural design of evidentiary procedure (inclusive of investigation). Specifically advocated are devices that exploit the cognitive psychological shortcomings of individuals and the sociological fragility of their collusive arrangements.