David A Love writes: The US criminal justice system is a broken machine that wrongfully convicts innocent people, sentencing thousands of people to prison or to death for the crimes of others, as a new study reveals. The University of Michigan law school and Northwestern University have compiled a new National Registry of Exonerations – a database of over 2,000 prisoners exonerated between 1989 and the present day, when DNA evidence has been widely used to clear the names of innocent people convicted of rape and murder. Of these, 885 have profiles developed for the registry’s website, exonerationregistry.org.

The details are shocking. Death row inmates were exonerated nine times more frequently than others convicted of murder. One-fourth of those exonerated of murder had received a death sentence, while half of those who had been wrongfully convicted of rape or murder faced death or a life behind bars. Ten of the inmates went to their grave before their names were cleared.

The leading causes of wrongful convictions include perjury, flawed eyewitness identification and prosecutorial misconduct. For those who have placed unequivocal faith in the US criminal justice system and believe that all condemned prisoners are guilty of the crime of which they were convicted, the data must make for a rude awakening.

“The most important thing we know about false convictions is that they happen and on a regular basis … Most false convictions never see the light of the day,” said University of Michigan law professors Samuel Gross and Michael Shaffer, who wrote the study.