Since 1989, more than 3,000 inmates have been exonerated in the United States, which translates to nearly 27,000 lost years behind bars. But those set free are just a small number of those who remain unseen.
University of Michigan law professor Samuel Gross says there are countless other innocent prisoners unable to get their cases reexamined to one day be overturned. He is a senior editor of the National Registry of Exonerations, which has released its annual report.
Founded in 2012, the registry is a project of the U-M Law School, Newkirk Center for Science & Society at the University of California, Irvine, and Michigan State University College of Law. It provides detailed information about every known exoneration in the United States since 1989—cases in which a person was wrongly convicted of a crime and later cleared of all the charges based on new evidence.
Gross discusses the registry’s 10-year history and the future of exonerations.
What is the story behind your interest in exonerations?
It developed from work I did on the death penalty. In 1996, I published an article in which I argued that false convictions are likely to be more common among death sentences (and other convictions for aggravated murders) than among lesser crimes of violence. That led to a general interest in the frequency and nature of convictions of innocent people.
In 2005, with several students, I published a study of 340 exonerations in the U.S. since 1989—the largest general list of such cases with the most detailed analysis at that time. But I knew when I wrote it that I missed many other cases because, as I phrased it, “there is no national registry of exonerations.” For several years I tried to get others to create something like that, but by 2010 I realized no one would. So I took it on myself, with other collaborators, especially Rob Warden, then the executive director of the Center on Wrongful Convictions at the Northwestern University College of Law. We had no idea what it would look like, let alone what it would grow into.
What challenges did you encounter during those initial years?
The main challenge was—and still is—limited funding. It’s a serious issue now, but before 2012 we were working on a shoestring budget. We cobbled resources together and relied heavily on law student research assistants who did the bulk of the initial work organizing and coding the cases. In addition, we had excellent help from the U-M Law School’s IT staff.
Where are most exonerations occurring?
The leading states are Illinois, Texas, New York, California and Michigan (numbers can be found at The National Registry of Exonerations).
One major factor is population. The top four are all big states. But why does Illinois (12.6 million residents) have so many more than California (39.6 million residents) and five times as many as Florida (29.6 million residents)? Part of the reason might be a higher rate of false convictions. Chicago, for example, is known as the national capital of coerced false confessions.
But I don’t think that’s the main reason, and it might not even be a factor. It’s clear that we miss the great majority of wrongful convictions, and we don’t know anything about those we don’t see, including where they occur. The states with high numbers of exonerations are those in which, historically, the issue has received a lot of attention and resources. In Chicago, the leading contributors were the Chicago Tribune (before it was dismembered), which published a huge amount of pathbreaking journalism on false convictions in Cook County, in Illinois generally and across the country; and the Center on Wrongful Convictions—and a very active civil rights and plaintiffs’ bar.
In New York, the obvious impetus was the original and still leading Innocence Project, aided by an active bar of substantial local and regional journalism. By contrast, California had no comparable assets until recently. Michigan’s high numbers are due in large part—in historical order—to the State Appellate Defender’s Office, the U-M Law School’s Innocence Clinic and the Wayne County DA’s Office’s Conviction Integrity Unit.
When people think of wrongful convictions, they often consider TV crime shows that feature cases involving DNA. Is that what you’re seeing through the registry data?
Yes, many people still think that “exoneration” is the second word of a two-word phrase that begins with “DNA.” In fact, DNA exonerations have always been a minority—about 18% of the overall total, down to 12% of exonerations in 2021. But DNA exonerations have been disproportionately important in raising public and professional awareness of the problem of convictions of innocent people, and in teaching us about some of the causes of these terrible errors.
Describe the cases that get overturned.
The most common causes of false convictions that we know of from exonerations are perjury and other false accusations (61% of cases), governmental misconduct of many sorts (56%), mistaken identifications by eyewitnesses (27%), false or misleading forensic evidence (24%) and false confessions (12%).
The reasons why these things occur vary widely. Some eyewitness mistakes are just that; some are generated by suggestive and misleading identification procedures by police officers. Some misconduct is caused by laziness or lack of resources; some is part of determined efforts to secure convictions even if the evidence will not support them. And so forth.
These are the reasons for the false convictions we know about. There are many that we don’t know about, for one reason or another. I’d say that numerically, the most common cause of false convictions is the pretrial detention of defendants who can’t make bail. That confinement leads some innocent defendants in low-level cases to take plea bargains that will allow them to go home immediately, or in days, rather than wait for months in jail before trial. But that’s just an educated guess. We almost never see those cases among the exonerations we list. It’s very hard to obtain an exoneration after a guilty plea, and hardly anyone ever tries for a misdemeanor or low-level felony.
In reviewing the registry, African Americans comprise most of the exonerations. What does this say about our justice system and law enforcement?
African Americans comprise a small percentage of the American population, but a majority of innocent defendants wrongfully convicted of crimes and later exonerated. For most offenses, such as murder, sexual assault and drug crimes, African Americans spend several years longer in prison than whites convicted of the same crime. Their cases are significantly impacted by racism, mistaken eyewitness identification and police bias, which includes racial profiling involving unlawful police stops, searches and arrests.
After publishing this data for 10 years, what is your overall assessment?
I think it’s clear that innocent people are convicted of serious crimes in the United States on a regular basis. We don’t know how many, but an accumulation of data from several sources suggests that it might be in the range of 1%-2% of felony convictions, if not higher. There are about a million felony convictions in the United States each year, which suggests at least 10,000 false felony convictions. Misdemeanor convictions are estimated at over 4 million a year.
We have even less information about the frequency of wrongful convictions in misdemeanor cases, but it probably dwarfs the number of innocent defendants who are convicted of felonies. Only a small percentage of those innocent defendants obtain exonerations—perhaps one or two in a hundred, primarily among those convicted of the most serious crimes and sentenced to death, life or decades in prison.
There are some indications of improvements over the past few decades. Because of pretrial DNA testing, innocent defendants are much less likely to be convicted of sexual assaults in cases where the only question is the identity of the criminal. And it appears that police officers are much less likely to use violence in interrogations of innocent defendants than they were in the 1980s and ’90s. That’s encouraging. But for the most part, I see no evidence that we have solved the problems that lead to the conviction of many innocent defendants—and that traps most of them with no remedy.