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Quantifying Reasonable Doubt

Quantifying Reasonable Doubt. Mexico City Mini- Foro September 4-5, 2009 Harry Saunders. AGENDA. Thesis Motivation Objections Discussion. The Thesis:. BARD does not exist. To establish BARD, it must be quantified.

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Quantifying Reasonable Doubt

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  1. Quantifying Reasonable Doubt Mexico City Mini-Foro September 4-5, 2009 Harry Saunders

  2. AGENDA • Thesis • Motivation • Objections • Discussion

  3. The Thesis: • BARD does not exist. • To establish BARD, it must be quantified. • Failure to do so will create endless, and thorny, problems. • It can be done. Practically and legally.

  4. AGENDA • Thesis • Motivation • Objections • Discussion

  5. The Experiment (Subjects): • Corporate managers • Trained in Decision Analysis. • Biases cognizant. • Required to apply the methodology in their work. • Responsible for results of their decisions. • Generally trained, often to post-graduate level, in engineering or the sciences. Some with added business degrees. • Junior academics • Trained in Decision Analysis. • Mostly post-docs; some PhD students.

  6. The Experiment (Setup): • Subjects were asked to place themselves in the following situation: • a defendant has been charged with murder • you have been selected to serve on the jury • a guilty verdict opens the door to the death penalty • you believe the law under which the defendant has been charged is a just law • you believe the defendant has been brought to trial honestly and ethically

  7. A jury’s alleged role is to change uncertainty into legal “fact.” Evidence, Argument, Jury Deliberations Prior Assessment Posterior Assessment Legal “Fact” (guilty or not guilty) p(guilty) =x p(guilty) = 0? (“Presumed Innocent”) p(guilty) = 0 or 1 (“Reasonable Doubt” or “Beyond Reasonable Doubt”)

  8. Question: How large does “x” have to be to convict? • “A defendant in a criminal action is presumed to be innocent until the contrary is proved, and in the case of a reasonable doubt whether [his/her] guilt is satisfactorily shown, [he/she] is entitled to a verdict of not guilty. This presumption places upon the People the burden of proving [him/her] guilty beyond a reasonable doubt.” • “Reasonable doubt is defined as follows: It is not a mere possible doubt; because everything relating to human affairs is open to some possible or imaginary doubt. It is that state of the case which, after the entire comparison and consideration of all the evidence, leaves the minds of the jurors in that condition that they feel an abiding conviction of the truth of the charge.” The judge reads you the instructions:

  9. Based on the evidence, you believe the probability the defendant is guilty is x. • The actual value of x is immaterial to this exercise, but you have reached some assessment of it. • What is the minimumvalueofx needed for you to be convinced “beyond a reasonable doubt”? • That is, how big does x have to be for you, personally, to convict? Individual Exercise (Anonymous) Probability (guilty) > ___ ?

  10. The Results: • Excel charts

  11. The Motivation: • Jurors face an impossible task with the current instructions. • Serious Due Process problems and possibly Equal Protection problems are evident.

  12. Constitutional Justification (and latitude): • Due Process • Quantitative standard not foreclosed • Grandfathering is a possibility • Equal Protection? • Quantitative standard not foreclosed • Grandfathering is a possibility

  13. AGENDA • Thesis • Motivation • Objections • Discussion

  14. Objections: • You can’t quantify that. Too many imponderables.

  15. Events: • It rains here tomorrow. • Mexico wins the next World Cup. • The Korean Peninsula reunites within 10 years. • The Dow Jones Industrial Average rises above 15,000 before January 1, 2012. • My spouse divorces me in the next 10 years. • The jury in [insert case] returns a guilty verdict. • The defendant in this case on which I am serving as a juror is guilty.

  16. Probability Wheel Demo

  17. The Probability Encoding: REWARD OUTCOME Red Win $100 Million WHEEL Win $0 Blue Win $100 Million Event happens EVENT Win $0 Event does not happen

  18. The reward does not matter, so long as the structure is symmetric across the decision. REWARD OUTCOME Red Get to Live WHEEL Shot Dead Blue Get to Live Event happens EVENT Shot Dead Event does not happen

  19. A specific event (the oil executive): REWARD OUTCOME Red Win $100 Million WHEEL Win $0 Blue Win $100 Million Producing well EVENT Win $0 Dry hole

  20. Narratives: • Two geology & geophysics (G&G) teams are proposing two different stories for what can be seen. • The executive must listen to each case and then assess his probability that the well will be successful.

  21. AGENDA • Thesis • Motivation • Objections • Discussion

  22. Objections: • You can’t quantify that. Too many imponderables. • It will throw us into chaos: everyone will demand retrials. • Jurors should be the ones deciding the standard of proof. • Trials will become like computers, and jurors like calculators. • If it’s such a big problem, why hasn’t it surfaced before? • It has worked for hundreds of years.

  23. Blackmun quote: “To be a meaningful safeguard, the reasonable-doubt standard must have a tangible meaning that is capable of being understood by those who are required to apply it. It must be stated accurately and with the precision owed to those whose liberty or life is at risk.” – Justice Harry A. Blackmun

  24. AGENDA • Thesis • Motivation • Objections • Discussion

  25. The Fourteenth Amendment Section 1. “…No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.”

  26. Due Process • Precedents • Open to Challenge? • Grandfathering?

  27. Precedents • Victor v. Nebraska • “The beyond a reasonable doubt standard is a requirement of due process, but the Constitution neither prohibits trial courts from defining reasonable doubt nor requires them to do so as a matter of course.” They only require that if a jury instruction is given, that, “ ‘taken as a whole, the instructions [must] correctly conve[y] the concept of reasonable doubt to the jury.’ ”

  28. Open to Challenge? • Precedent (Victor v. Nebraska) apparently forecloses challenge to BARD as currently defined on due process grounds. • Difficult, or impossible, to find a case that would open the door. • But this does not prevent the quantification of BARD.

  29. Grandfathering • Procedural rule change vs. substantive rule change • Substantive rules apply retroactively • Procedural rules apply retroactively if they are “watershed’ rules • Substantive vs. procedural rules • A rule change is substantive if it alters the range of conduct or the class of persons the law punishes • A rule change is procedural if it regulates the manner of determining the defendant’s culpability • DeStefano v. Woods • 6th Amendment right to a jury trial • Ruled NOT a substantive rule change; no retroactive application

  30. “Watershed Rules” • A watershed rule is one without which the likelihood of an accurate conviction is seriously diminished. • Schriro v. Summerlin • Jury must decide sentence, not a judge • Ruled NOT a watershed rule; does not apply retroactively • Argument: • Quantifying BARD is procedural, not substantive • Clarifies an existing standard • Even if it is substantive, it is arguably not a “watershed” rule change

  31. Equal Protection • Johnson v. Louisiana • In Louisiana, different crimes call for different jury voting protocols (for lesser crimes, super-majority of 9/12 required; major crimes require unanimity). • Challenged on due process and equal protection grounds. • Equal protection argument: defendants charged with different crimes become distinguishable “classes.” • The Court ruled for Louisiana. • Justice Powell on the equal protection argument: • “Such distinctions between classes of defendants do not constitute invidious discrimination against any one of the classes unless the State's classification can be said to lack a reasonable or rational basis.” • Note that Justice Powell did NOT challenge that these were different classes. • Not a large step from here to the conclusion that defendants subject to different standards of proof constitute different classes (like defendants subject to different jury voting protocols).

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