1. Recent Research on Expert Witnesses May Help Reduce Error Rates in the Forensic Sciences Roger Koppl Fairleigh Dickinson University Lawrence Kobilinsky John Jay College

2. Summary Forensic scientists are expert witnesses There is social science literature on expert witnesses We can learn from this literature Studying the literature on social science may help us reduce the error rate in forensic science A taxonomy of errors is proposed

3. Why Bother? Errors are bad The forensic science community has come under fire We do not yet have an effective strategy of response to recent challenges “Forensic science administration” (based on the expert witness literature) may be part of such a strategy

4. Two models of the forensic scientist

7. Our Model

9. In other words A real human being Whom we study in a scientific manner

10. The literature in expert witnesses Views expert witnesses as human beings Recognizes that human beings respond to their social environment, which may induce or inhibit errors Helps us to seek ways of reducing error rates by re-organizing that social environment

11. Some names from the existing literature

12. Forensic Science Larry S. Miller “Procedural Bias in Forensic Science Examinations of Human Hair,” Law and Human Behavior, 1987, 11:157-163.

13. Sociology, Philosophy, and Science Studies Karl Mannheim –David Bloor –Simon Cole –Steve Fuller Robert K. Merton –Alvin Goldman –Philip Kitcher –Kobilinsky and Koppl

14. Economics Susan Feigenbaum and David M. Levy Luke M. Froeb and Bruce H. Kobayashi. –“Naive, Biased, yet Bayesian: Can Juries Interpret Selectively Produced Evidence?” Journal of Law, Economics, and Organization, 1996, 12: 257-276.

15. Law and Psychology Itiel Dror. –“When Emotions Get the Better of Us: The Effect of Contextual Top-down Processing on Matching Fingerprints,” Applied Cognitive Psychology, 2005, 19: 799-809. Richard Posner –“An Economic Approach to Legal Evidence,” Stanford Law Review, 1999, 51: 1477-1546.

16. Lessons Institutions matter because they create a social environment Forensic scientists respond to their social environment The right social environment minimizes errors The social environment of forensic science should be similar to that of pure science

17. Applying the lessons of the literature on expert witnesses Means reducing the error rate in forensic science Requires a useful classification of errors

18. Forensic-science Errors Task-based errors –explained by considering the underlying phenomena being examined. Agent-based errors –explained by considering the properties of the forensic scientist.

19. Agent-based Errors Errors against nature –May emerge even when procedures are followed Errors against standard –Emerge only when procedures are not followed

20. Forensic science errors Task-based errors Agent-based errors Errors against nature Errors against standard

21. Forensic Science Administration Applies the literature on expert witnesses to forensic science Studies Agent-based errors –Errors against nature –Errors against standard Suggests ways to alter the institutions of forensic science that may reduce the frequency of errors

22. So What? We have a research program designed to reduce error rates in forensic science This research program may help the forensic science community respond to recent challenges And reduce error rates