This paper deals with two issues related to exoneration cases: On the one hand, it examines the relative number of lineups used as the method of identification that resulted in mistaken identifications and false convictions. On the other, it compares eyewitness error as a cause of false convictions with other common causes. The original intent of the study was to concentrate only on the first topic. After defining some of the terms used in this paper, we will first outline our interest in the first issue, and then explain the widened focus of the paper.