Tigers, black swans, and unicorns: The need for feedback and oversight

Humans have a decision-making system which is biased to avoid costly false negatives while the criminal justice system is designed to be biased in the opposite way, avoiding costly false positives. But systems fail, people do not; a badly out of kilter system can lead even the most expert to bad outcomes. Perverse incentives, driven by the fetishizing of DNA, put pressure on an already-stressed forensic system. Every system needs feedback, both positive and negative, to correct itself and stay stable, forensic science is only one of those in a criminal justice system. Recognizing false positives, false negatives, and how they happen is critical to stabilizing and calibrating a criminal justice system. Oversight, review, and addressing wrongful convictions is a necessary form of feedback to forensic science and any balanced and fair criminal justice system.