Why do police officers, investigators, prosecutors, judges, and others with an interest in eliciting accurate memory-based testimony need to inform themselves of the research literature in experimental psychology that addresses the question of witness memory? The answer is straightforward, from the perspective of a simple cost/benefit analysis. As with so many matters in the administration of public funds, effectiveness holds important rewards. Those who investigate crimes and decide which line of investigation to pursue and which line to postpone or set aside, necessarily make judgments...