Reuters/Joshua Lott    When Beverly Monroe met her new neighbors in the free world after spending seven years in a Virginia prison for a crime she didn’t commit, she spoke candidly about her past. “I said I’d been through a crisis,” she says. “People immediately think a divorce or you lost your husband or something like that, which is all terrible enough.”

Monroe did lose her longtime boyfriend, Roger de la Burde, who was found shot to death with his own handgun in 1992. An overzealous state police agent suspected foul play, even though officials initially believed that de la Burde had shot himself. Monroe’s statements to police, which were deemed to be self-incriminating, coupled with an informant who received a deal from the prosecution in exchange for her testimony, formed the basis for the case against her. At 54, the mother of three was charged and convicted of murdering de la Burde and sentenced to twenty-two years at the Pocahontas Correctional Center. Monroe might have served the whole sentence had her attorneys not discovered a collection of concealed exculpatory documents, including a crucial medical examiner’s report from 1999 that strongly suggested that de la Burde had indeed committed suicide. In 2002 a US District Court judge vacated the conviction.

Now in her 70s, Monroe works as an administrative assistant. The lost income and lack of savings from her years behind bars have made retirement a distant dream. “I’ll have to work until I’m 105,” she says. Virginia has not compensated her for the years lost to prison or for her legal expenses. (Her trial cost nearly $200,000.)

“Being innocent in prison is real torture,” Monroe says. “It’s a lasting kind of trauma…. You’re released, and you realize that it didn’t just happen to you—it’s happened to other people who have had it so much worse.”

How many other people? No one knows. The Bureau of Justice Statistics doesn’t track exonerations, so for years that task has fallen to lawyers, academics and activists relying on news reports and legal filings. While the Innocence Project and the Death Penalty Information Center track exonerations, neither group’s database is complete. No single resource has amassed all of the known exoneration cases.

Until now. On May 21, the University of Michigan Law School, in conjunction with the Center on Wrongful Convictions at the Northwestern University School of Law, released the first-ever National Registry of Exonerations. The searchable online database is the most credible and comprehensive resource on wrongful convictions in the United States. Peter Neufeld, the co-founder and co-director of the Innocence Project, has called it the “Wikipedia of Innocence.” The registry, which can be viewed at exonerationregistry.org, currently counts 891 cases since 1989, the year of the first exoneration achieved using DNA.

The scope is significant: reliable data on false convictions had been limited to DNA exonerations and death row exonerations. Beverly Monroe doesn’t fit either category, and neither would the vast majority of exonerated prisoners: less than 1 percent of the nation’s prison population is on death row, and DNA evidence applies only to a small fraction of all criminal cases—those with biological evidence like semen, blood, hair and saliva.

In addition to examining “a much broader group of exonerations,” according to University of Virginia law professor Brandon Garrett, the registry shows “that there are a lot of exonerations that don’t get a lot of press attention.” It also alters the conventional wisdom about how innocent people get convicted. For his 2011 book, Convicting the Innocent, Garrett scoured the first 250 DNA exonerations and identified eyewitness misidentification as the leading cause of those wrongful convictions (as have others). But the larger pool of cases reflected in the registry reveals other trends. According to University of Michigan law professor Samuel Gross, “perjury or false accusation” is the leading cause of wrongful conviction.

Although the majority of the registry’s cases involve violent crimes such as murder, rape and sexual assault, exonerations for nonviolent crimes are better represented than ever before. The exonerated spent an average of eleven years in prison; ten people were exonerated posthumously or died in prison. Roughly 50 percent of the cases involved African-American defendants.

Gross believes that the cases in the database are just the tip of the iceberg. Indeed, his total tally of exoneration cases actually exceeds 2,000, out of which more than 1,100 were “mass exonerations,” omitted from the registry for fear of skewing the statistics. Mass exonerations are often the result of police misconduct. Gross estimates a wrongful conviction rate among violent felonies of up to 4 percent. “Would I venture a guess about other types of crimes—drug crimes or white-collar crimes? Not at all,” he says. “Misdemeanors? Who knows?”

Recent evidence suggests that the error rate could be even higher. After a series of exonerations in Virginia, then-Governor Mark Warner ordered a review of thousands of cases over a fifteen-year span before DNA testing was available. The massive endeavor was recently completed, revealing an error rate that hovered at 6 percent, which Gross considers “horrifying.” Extrapolating to the whole US prison population, this could mean that more than 136,000 people are unjustly incarcerated.

Many wrongful convictions cannot even justly be called ”errors.” Beverly Monroe’s post-conviction attorneys discovered that prosecutors had concealed their promise of a reward to the informant, Zelma Smith—she received a sentence reduction in exchange for her testimony—as well as information about Smith’s pattern of offering information in other, unrelated cases with the expectation of a reward.

“When someone testifies falsely under oath, that’s not a mistake,” Monroe says. Her case entry in the National Registry lists the following contributing factors: “false confessions, false or misleading forensic evidence, perjury or false accusation, and official misconduct”—an unpalatable sampling of the many flavors of wrongful conviction.

The running tally of exonerations in the registry is important, but of greater significance is the analysis and categorization of cases, which will make new research possible and help curb misconduct. For exonerees who received little media attention or recognition from the state, the registry may assist in their efforts to clear their name and receive compensation. If nothing else, the public acknowledgment of their wrongful conviction lends legitimacy to their struggle.