Justice Scalia inflates the denominator

With math skills like this, it's no wonder Antonin Scalia went to law school:

A couple of years ago, Justice Antonin Scalia, concurring in a Supreme Court death penalty decision, took stock of the American criminal justice system and pronounced himself satisfied. The rate at which innocent people are convicted of felonies is, he said, less than three-hundredths of 1 percent — .027 percent, to be exact.

That rate, he said, is acceptable. “One cannot have a system of criminal punishment without accepting the possibility that someone will be punished mistakenly,” he wrote. “That is a truism, not a revelation.”

But there is reason to question Justice Scalia’s math. He had, citing the methodology of an Oregon prosecutor, divided an estimate of the number of exonerated prisoners, almost all of them in murder and rape cases, by the total of all felony convictions.

“By this logic,” Samuel R. Gross, a law professor at the University of Michigan, wrote in a response to be published in this year’s Annual Review of Law and Social Science, “we could estimate the proportion of baseball players who’ve used steroids by dividing the number of major league players who’ve been caught by the total of all baseball players at all levels: major league, minor league, semipro, college and Little League — and maybe throwing in football and basketball players as well.”

Joshua Marquis, the Oregon prosecutor cited by Justice Scalia, granted the logic of Professor Gross’s critique but not his conclusion.

“He correctly points out,” Mr. Marquis, the district attorney in Clatsop County, Ore., said of Professor Gross, “that rape and murders are only a small percentage of all crimes, but then has absolutely no real data to suggest there are epidemic false convictions in, say, burglary cases.”

Writing in the Boston Globe Ideas section, David Feige offers a more detailed critique of Marquis's claims back in 2006:

Marquis's most glaring error is his failure to acknowledge the fact that most felony arrests aren't contested. In fact, 95 percent of them are resolved by plea rather than trial. Thus in 19 out of every 20 felony cases, there is no contested issue of guilt and no real claim of error.

Only trials in which someone is convicted while maintaining his innocence should be considered in computing an error rate. Of Marquis's 15 million felony cases, 14.25 million were pleas. When the denominator in his fraction is changed from 15 million to 750,000, the error rate jumps from the arguably ignorable 3 in 10,000 to more like 50 in 10,000.

And Marquis's numbers become even more disturbing with further analysis. Because of the overwhelming demands involved in reinvestigating a crime with an eye toward exoneration, it is almost exclusively defendants sentenced for rapes and murders whose cases get scrutiny from groups like the Innocence Project, the nonprofit organization that helped free Alan Newton. The chances that a drug defendant is going to interest them are virtually nil. Thus the only people who have any meaningful access to the possibility of exoneration are a tiny subset of criminal defendants. Murders constitute only 0.8 percent of all felony cases, and rapes less than 2 percent. In other words, less than 450,000 of Marquis's 15 million felony convictions came in cases where the defendant has had a real shot at exoneration.

It is true that murder cases go to trial far more often than run-of-the-mill drug sales or check forgeries. In fact, some 44 percent of murder cases actually go to trial, with an average conviction rate of about 85 percent. But even taking this into account, of the 150,000 murder cases in Marquis's 15 million, only 66,000 homicide defendants maintained their innocence through a trial, of which just over 56,000 were convicted. Using similar trial and conviction rates for rapes yields somewhere south of 200,000 contested convictions in serious cases. In the final analysis, Marquis's error rate is off by orders of magnitude-his vision of a virtually error-proof system is simply unsupported by the numbers.

Comments

[Northern Observer]

I have said it once (the Scalia separate opinion on Lawrence Vs Texas)and I will say it again. Anthony J. Scalia is not fit to sit on the Supreme Court of the United States of America. He should step down and failing that he should be impeached. He is a disgrace to the law.