Some tales of wrongful conviction are well known, like the case of amateur boxer Dewey Bozella.
Bozella was found guilty in 1983 for the murder of an elderly woman. New York police and prosecutors pressed second-degree murder charges propped up by the testimony of witnesses who eventually recanted their testimony. It wasn't until 2007 that Bozella's attorneys discovered major discrepancies and evidence pointing to another suspect, leading to Bozella's release in 2009.
But many stories involving tainted evidence, malingering law enforcement and mistaken eyewitness identification never become common knowledge. The cases outlined on the new National Registry of Exonerations are likely just a fraction of the wrongful imprisonment cases in the United States, researchers told The Huffington Post.
More than 2,000 inmates and ex-cons have been exonerated since 1989, according to the database that aims to track all wrongful convictions in the United States. More than 100 had been sentenced to death.
"This is a beginning," said University of Michigan Law School professor Samuel Gross, one of the database's creators. "One of my great hopes is that this will lead us to learn more about exonerations."
The database, which was developed with members of Northwestern University's Center on Wrongful Conviction, focused on 873 individual cases. The researchers also identified 13 major police scandals that falsely netted 1,170 other people, although these are not included in the database because they are the results of a collective exoneration based on problems in individual agencies.
Among the findings by the database researchers:
"The most important goal of the [criminal justice] system is accuracy," Gross told HuffPost. "Getting the right person and not getting the wrong person are obviously the most important goals. The only way to get those are to learn how we made our mistakes."
One reason Gross and his colleagues believe they're just scratching the surface there are geographical clusters that they found, like Chicago's Cook County -- which leads the country with 78 exonerations. There are other densely populated counties, like Fairfax, Va., that don't have any exonerations.
Areas with high numbers of freed men and women aren't necessarily more prone to police misconduct or overzealous prosecutors, Gross said. "I'm very sympathetic to police officers," he said. "They're overworked and they're right most of the time. But most of the time is not all the time."
Often the work of an aggressive organization like the Northern California Innocence Project in Santa Clara County, which the database shows has had 10 exonerations, can be behind the cases. Nearby Alameda County, where there is no such organization, has no exonerations, Gross said.
A high number of exonerations in certain states also might mean that legal watch groups there are more active and effective.
Dallas County in Texas has had 21 exonerations since 2007 -- the most in the country for that period, according to the researchers. That coincides with the election of District Attorney Craig Watkins, the first black D.A. in Texas. Early in Watkins' term, he created a Conviction Integrity Unit to review claims of innocence.
"It says that we're working the hardest to correct past wrongs," said Russell Wilson, who runs the special unit. "There's no reason to believe that other large population centers wouldn't have had the same or similar results."
The work by the Dallas district attorney was made easier by office's record keeping; unlike many other counties, it sent DNA evidence to a lab that has properly stored the material for decades.