National innocence data understated by excluding drug war exonerations

Adam Liptak has an article in the New York Times ("Consensus on counting the innocent: We can't," March 25) making a statistical point nationally about exonerations that I'd made previously for Dallas County, Texas' exoneration capital: The total exonerations routinely counted only include cases overturned through DNA evidence, but a lot more innocent people are exonerated than that. Indeed, Liptak's discussion shows why many of the numbers for innocent people convicted that are routinely bandied about have little validity at all, because they exclude so many offenses. Wrote Liptak:

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.” ...

What the debate demonstrates is that we know almost nothing about the number of innocent people in prison. That is because any effort to estimate it involves extrapolation from just two numbers, neither one satisfactory.

There have been 214 exonerations based on DNA evidence, almost all of them in rape cases, according to the Innocence Project at the Cardozo School of Law. But there is no obvious control group to measure these exonerations against.

Virginia, though, has discovered thousands of closed rape files from 1973 through 1988, many with untested biological evidence. DNA testing of a preliminary sample of 31 of them yielded two wrongful convictions. Those numbers are too small to be reliable, of course, but they would suggest a false conviction rate of 6 percent.

Even that rate may be low, said Shawn Armbrust, the executive director of the Mid-Atlantic Innocence Project. Ms. Armbrust said investigators in Virginia were able to get results in only 22 of the 31 tests, suggesting a false conviction rate of 9 percent.

The other important number comes from death row. According to the Death Penalty Information Center, 127 death row inmates have been exonerated.

Here we do have a control group. There have been more than 7,000 death sentences since the Supreme Court reinstated the death penalty in 1976.

But exoneration in the capital context is a funny concept. It suggests complete vindication, but its real meaning is generally narrower. ...

Professor Gross concluded that the false conviction rate for death row inmates has ranged from 2.3 percent to 5 percent. Were even the lower end of that range applied to people who received prison sentences of a year or more in the last three decades, he wrote, it would suggest that about 185,000 innocent people have served hard time.

But extrapolating from capital crimes to felonies generally is problematic whatever the number of exonerations.

Scalia's number is surely low. Most defense attorneys certainly think the number of innocent people who plea guilty among their clients is higher than that by orders of magnitude. Indeed, the counts of individual exonerees seem incomplete on their face. If, as Liptak says, all estimates of innocent people being convicted come from DNA exonerees and death row, that's a very narrow data pool.

I don't keep a running tab, though maybe I should start, but I try to pay attention to most of Texas' innocence cases. Far and away, if Texas' statewide figures are any guide, drug crimes account for as many or more wrongful convictions than rapes or capital murders. Our Texas media, though, has made the same counting error identified by Liptak. The Dallas Morning News' count of exonerees since 2001 excluded exonerees from the Dallas fake drugs scandal, for example. I wrote in January that their:

headlines trumpeting fifteen recent Dallas exonerations actually understate the problem. A lot more innocent people than that have seen their convictions overturned in Dallas since 2001.

At a minimum, another 24 people were wrongfully convicted in Dallas as part of the "fake drug" scandal and were ultimately exonerated. That makes the current total 39 people exonerated since 2001.

There very well may be more.

Similarly, if you were going to create a true statewide number of exonerees for Texas since 2001, you'd have to include about three dozen pardoned from Tulia, another dozen or so exonerated in Hearne, and quite a few others, the majority stemming from the drug war. That number easily surpasses in short order the number of DNA-based exonerations that are happening (mostly) in Dallas and Houston.

So no, it's true, we don't know how many innocent people have been convicted and exonerated, much less how many more are languishing in prison, either for violent crimes or lesser offenses. However, I think it's a positive sign that at least people are beginning to ask the question, and demand more accountable answers.

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