Innocence Project Notes

Time stated 90% of prisoners are there without physical evidence [Barry Scheck, Time May 31, 2010 p.29]

Barry Scheck stated on CNN that DNA labs error 20% of the time.

A pre-2010 version of the U of W Innocence Project website stated victims of rape falsely identify their attackers 25% of the time and there is no reason to believe the error rate in other areas of law for which DNA is not applicable is any less.

The June 2001 issue of Harvard Business Review contains an article saying generic testing shows people with 90% confidence answer questions correctly 70%-80% of the time.  

Notice the corresponding error rate is 20%-30%, consistent with rape error.  Therefore, it is statistically likely that 25% of all prisoners are entirely innocent based on human error.  The article's author said the figure could apply to court trials.

A paperback version of Scheck's groundbreaking book has a chart stating 50% of the error is due to police and proscutor misconduct.  The addition of intentional misconduct to generic human error could account for the 90% in prison without evidence figure.

In addition there appears to be a certian predisposition of juries to believe the state when the state often has more practice lying people into prison than private lawyers do in defending against it.