Supreme Court Justice Antonin Scalia said that the rate at which innocent people are convicted of felonies is less than three-hundredths of 1 percent – .027 percent, to be exact. He divided an estimate of the number of exonerated prisoners, almost all of them in murder and rape cases, by the total of all felony convictions. Joshua Marquis, an Oregon prosecutor cited by Scalia, said a critic, University of Michigan Law Prof. Samuel Gross, correctly noted that rapes and murders are only a small percentage of all crimes, but “has absolutely no real data to suggest there are epidemic false convictions in, say, burglary cases,” the New York Times reports.
What the debate demonstrates, says the Times, is that we know almost nothing about the number of innocent people in prison. That is because any effort to estimate it involves extrapolation from just two numbers, neither one satisfactory. There have been 214 exonerations based on DNA evidence, almost all of them in rape cases, according to the Innocence Project at the Cardozo School of Law. There is no obvious control group to measure these exonerations against. The other important number comes from death row. According to the Death Penalty Information Center, 127 death row inmates have been exonerated. There have been more than 7,000 death sentences since the Supreme Court reinstated the death penalty in 1976. But death row exonerations can be based on all sorts of things, like, say, prosecutorial misconduct. In other words, it is possible to wrongfully convict a guilty defendant.
Link: http://www.nytimes.com/2008/03/25/us/25bar.html?_r=1&hp&oref=slogin