In my spare time, I'm preparing a compilation of essays on various estimates of our country's wrongful conviction rate. As I draft them, I'll publish them here. When I'm done with all of them, I will compile them into a single document and make it available on Scribd for free, and on Amazon for a minimal cost.
The chapters will be numbered according to the predicted wrongful conviction rate, in percent. I will begin with the lowest estimate and work my way up to the highest. Keep in mind that we have a lot of people incarcerated, around 2.5 million. That means a wrongful conviction rate of only 1%, if applicable to all those incarcerated, means we have wrongfully imprisoned 25,000 people. A wrongful conviction rate of 10% means we have wrongfully imprisoned a quarter of a million people.
It should be interesting to see what the various studies have to say. Let's get started.
THE SCALIA NUMBER
THE SCALIA NUMBER
Joshua Marquis is the district attorney of Clatsop County, the county residing on the mouth of the Columbia River, at the northwest corner of Oregon. His article “The Innocent and the Shammed” appeared in the January 26, 2006 issue of The New York Times. He therein presented his estimate of our country’s wrongful conviction rate.
In the Winter 2005 Journal of Criminal Law and Criminology, a group led by Samuel Gross, a law professor at the University of Michigan, published an exhaustive study of exonerations around the country from 1989 to 2003 in cases ranging from robbery to capital murder. They were able to document only 340 inmates who were eventually freed. (They counted cases where defendants were retried after an initial conviction and subsequently found not guilty as "exonerations.") Yet, despite the relatively small number his research came up with, Mr. Gross says he is certain that far more innocents languish undiscovered in prison.
So, let's give the professor the benefit of the doubt: let's assume that he understated the number of innocents by roughly a factor of 10, that instead of 340 there were 4,000 people in prison who weren't involved in the crime in any way. During that same 15 years, there were more than 15 million felony convictions across the country. That would make the error rate .027 percent -- or, to put it another way, a success rate of 99.973 percent.
Five months later, Justice Antonin Scalia published a concurring opinion in the case of Kansas v. Marsh. Scalia chided those who dissented, led by Justice David Souter, for suggesting that innocent people may have already been executed in the United States.
It should be noted at the outset that the dissent does not discuss a single case -- not one -- in which it is clear that a person was executed for a crime he did not commit. If such an event had occurred in recent years, we would not have to hunt for it; the innocent’s name would be shouted from the rooftops by the abolition lobby.
Souter’s dissent, however, did mention the study by Samuel Gross, mentioned above. Scalia dismissed that study by quoting directly from The New York Times article.
Of course, even with its distorted concept of what constitutes “exoneration,” the claims of the Gross article are fairly modest: Between 1989 and 2003, the authors identify 340 “exonerations” nationwide -- not just for capital cases, mind you, nor even just for murder convictions, but for various felonies. Joshua Marquis, a district attorney in Oregon, recently responded to this article as follows:
“[L]et’s give the professor the benefit of the doubt: let’s assume that he understated the number of innocents by roughly a factor of 10, that instead of 340 there were 4,000 people in prison who weren’t involved in the crime in any way. During that same 15 years, there were more than 15 million felony convictions across the country. That would make the error rate .027 percent—or, to put it another way, a success rate of 99.973 percent.”
Scalia then adopts the 0.027% error rate as fact.
The proof of the pudding, of course, is that as far as anyone can determine (and many are looking), none of cases included in the .027% error rate for American verdicts involved a capital defendant erroneously executed.
Ironically, Scalia had earlier in his opinion berated Souter and the other dissenters for parroting news articles without critical review.
Of course even in identifying exonerees, the dissent is willing to accept anybody’s say-so. It engages in no critical review, but merely parrots articles or reports that support its attack on the American criminal justice system.
Joshua Marquis made an elementary but critical mistake in his calculation. He divided his estimate of all those who might be exonerated by his estimate of all felony convictions. He should have instead divided by all felony convictions in which exoneration is reasonably possible.
Most felony convictions, for example, are for crimes such as burglary, assault, and drugs. Such crimes are frequently devoid of DNA evidence and typically result in sentences of less than ten years. Since DNA is the most powerful evidence of actual innocence, and since the average time from conviction to exoneration is ten years, people convicted of the lesser felonies are seldom exonerated, for reasons having nothing to do with guilt or innocence.
Rape and murder cases, on the other hand, constitute less than two percent of all felony convictions but represent ninety-six percent of all known exonerations. (See Samuel Gross’ rebuttal to Scalia’s opinion “Souter Passant, Scalia Rampant: Combat in the Marsh.”)
If Joshua Marquis were to correct his calculation from
(10 x 340) / (15,000,000)
(10 x 340) / (15,000,000 x 0.02 / 0.96)
as I believe he should, then his estimate would rise to 1.1%.
Marquis’ corrected estimate would still, however, depend entirely on the arbitrary multiplier he selected in the numerator. He simply assumed the Gross study had identified 10% of all the people wrongfully convicted. Had he assumed instead that the Gross study had identified all 100% of those wrongfully convicted, his corrected estimate would be 0.11%.
On the other hand, had Joshua Marquis assumed the Gross study identified only 1% of the factually innocent, a number which seems as reasonable to me as 10%, then his corrected estimate would indicate we wrongfully convict, by trial or plea bargain, 11% of all those people we charge with felonies.
Despite multiplying some numbers together and then dividing by another, the Scalia number is no more than a guess by a single prosecutor, a guess soon adopted by a supreme court justice who demonstrates no aptitude for the simplest of applied mathematics.