Wrongful Convictions Reported for 6 Percent of Crimes

DNA-based exonerations for wrongful convictions tend to make news. New evidence comes to light that wasn’t available during the original trial, and someone previously found guilty of a crime is suddenly cleared.
For capital crimes such as murder and rape, this happens in approximately 3 to 5 percent of cases, but Penn criminologist Charles Loeffler realized there was no such estimate for other crimes, those ranging from serious charges like armed robbery and aggravated assault to more minor crimes such as theft and drug possession. So he shaped a study with Jordan Hyatt, now at Drexel University but formerly a research associate at Penn, and Penn criminologist Greg Ridgeway.
Surveying an intake population of nearly 3,000 state prisoners in Pennsylvania, the researchers found that 6 percent reported being wrongfully convicted, results the team published in the Journal of Qualitative Criminology in April. This is one of the first estimates of its kind for the criminal-justice population as a whole.
“We view this as an upper-bound estimate. In other words, if people were going to be inaccurate, that would lead us to a true rate that’s lower than, rather than higher than, 6 percent,” Loeffler says. “Before we did this study, a reasonable response to the question of how many people are wrongfully convicted would be, ‘We don’t know.’ Through this work, we’ve reduced that uncertainty dramatically.”