Cory Maye and the n-guilty-men problem

Interviews with jurors in the Cory Maye case reinforce the idea that justice was ill-served at his trial; one of them was on so many “medications” for her “nerves” that she can’t remember much of what happened. The jury system allows too many false convictions, and judges ought to be more vigilant than they are about overturning verdicts based on inadequate evidence.

Radley Balko is still pursuing the Cory Maye case. (Since none of our paid newspeople want to do the work, maybe some newspaper should hire Balko as a stringer.) His latest post reports on his efforts to interview the two black women on the jury that convicted Maye.

One works for the county and didn’t want to talk for fear of repercussions at work, which raises questions about how independent she felt she could be as a juror. The other was taking so many “medications” for her “nerves” that she mostly doesn’t remember the trial, but it’s clear from what Balko reports her as saying that she wasn’t applying a “beyond reasonable doubt” standard to her vote to convict Maye. Asked whether he ought to have a new trial, she responds, “Oh, yes. He ought to get a new trial. Everybody deserves a chance.”

That must have been some voir dire!

All this reinforces the idea that Maye’s conviction was a travesty of justice.

But it also illustrates a broader point, made by John Stuart Mill and perhaps others before him: While the jury system is a valuable guard against some forms of day-to-day official oppression, a bulwark against the erection of a tyranny, and a valuable form of civic and moral education, it is not anything approaching a sensible way to determine the truth. All the jury research since Mill’s time just reinforces that observation.

Judges routinely overturn jury verdicts and awards in tort cases. They have the same authority to overturn convictions (not, of course acquittals), in addition to their authority to find the defendant “not guilty” without hearing the defense witnesses if the prosecution fails to carry its heavy burden of proof. They ought to use that authority more aggressively. But of course all the political pressures push them in the other direction.

I’m still very much a law-and-order hawk. That is, I believe that crime is so damaging and socially corrosive &#8212 especially so for poor people and members of socially disadvantaged minority ethnic groups &#8212 that it is worth inflicting great suffering on offenders and their families and friends to reduce the criminal riskiness of various social environments. But since we’re already convicting more people than we can effectively punish, the cost in crime-control terms of a false acquittal isn’t usually very great except when the defendant is a serious high-rate offender. The cost of a false conviction, by contrast, is enormous.

Statistical decision theory teaches us, when we face a tradeoff between two opposite errors, to set the ratio of the marginal error probabilities as the inverse of the ratio of the damages caused by the two kinds of error. That is, if saying “no” incorrectly costs me a dollar, and saying “yes” incorrectly costs me $99, then I should say “no” unless the probability that “yes” is the right decision is greater than 99%. The standard of “beyond reasonable doubt” suggests to my mind a ratio at least that high: since I can reasonably fear an outcome that is only 1% probable, I wouldn’t consider an outcome that is 99% probable “certain beyond reasonable doubt.” Thus the “reasonable doubt” standard, if interpreted literally, would appear to be consistent with Benjamin Franklin’s famous “Better that a hundred guilty persons should escape than that one innocent person should suffer.”

But Sasha Volokh’s playful article “n Guilty Men” reports that American lawyers &#8212 due, no doubt, to the failure of law schools to teach decision analysis &#8212 more conventionally set the ratio at ten-to-one, which implies that they are willing to treat an event as “certain beyond reasonable doubt” as long as its probability is greater than 91%. If that seems right to you, please get in touch with me; I want you in my poker game.

I wouldn’t, however, want you on my jury, or as my judge. Given how horrible American prisons are, and how many people they house, the extent of the injustice resulting if even a few percent of them are actually innocent is, or ought to be, intolerable. Much better to be more generous about what sort of evidence is admissible at trial &#8212 in particular, evidence of prior similar acts, even when those acts did not result in conviction &#8212 than to send people away when their odds of being innocent are no worse than the odds of filling an inside straight.

Author: Mark Kleiman

Professor of Public Policy at the NYU Marron Institute for Urban Management and editor of the Journal of Drug Policy Analysis. Teaches about the methods of policy analysis about drug abuse control and crime control policy, working out the implications of two principles: that swift and certain sanctions don't have to be severe to be effective, and that well-designed threats usually don't have to be carried out. Books: Drugs and Drug Policy: What Everyone Needs to Know (with Jonathan Caulkins and Angela Hawken) When Brute Force Fails: How to Have Less Crime and Less Punishment (Princeton, 2009; named one of the "books of the year" by The Economist Against Excess: Drug Policy for Results (Basic, 1993) Marijuana: Costs of Abuse, Costs of Control (Greenwood, 1989) UCLA Homepage Curriculum Vitae Contact: