(Bloomberg Law) -- How often does our justice system get it wrong, convicting innocent people of crimes they did not commit? A new project by the University of Michigan Law School and the Center for Wrongful Convictions at Northwestern University School of Law tries to answer that question.
In the last 23 years, more than 2,000 people have been convicted of serious crimes and later exonerated, the National Registry of Exonerations has found. By far the largest segment was almost 1,200 defendants falsely convicted because of large scale patterns of police corruption, generally in drug and gun cases. Of the remaining 873 defendants exonerated, nearly half were wrongly convicted of murder and, of that group, 101 were sentenced to death. On average, it took more than 11 years for a conviction to be set aside.
Why does the justice system get it wrong? In homicides, the biggest problem is perjury and false accusation, most often by supposed eyewitnesses. False convictions in adult rape cases are primarily based on mistakes by eyewitnesses, while false convictions in child sex abuse cases are often for fabricated crimes that never occurred.
Two thousand exonerations may seem small in a nation with more than 2.3 million people behind bars. But there are far more false convictions than the report contains. Most false convictions are never formally challenged, and those convictions that are successfully overturned receive little or no attention from the media, the report's authors say.