Benner, Laurence A., The Presumption of Guilt: Systemic Factors that Contribute to Ineffective Assistance of Counsel in California (September, 18 2009). California Western Law Review, Vol. 45, No. 263, 2009. Available at SSRN: http://ssrn.com/abstract=1475478
" ... The most frequent deficiency in attorney performance was the failure to conduct an adequate investigation with respect to guilt or innocence..."
And that's quite a deficiency.
