A sample of registered voters, selected to represent the court's list of prospective jury members, was given scenarios from eyewitness identification studies involving target-present lineups. Respondents' estimates of the hit rates in the three target-present situations were significantly greater than the actual hit rates in each of the three cases. The mean percentage of respondents overestimating the hit rates, averaged across the three cases, was 83.7 percent. The results indicate that awareness of the unreliability of eyewitness evidence does not appear to be part of the 'common knowledge' of prospective jury members. These data can be seen as refuting the claim made by some courts that expert testimony about eyewitness evidence would not tell the jury members anything they did not already know. A graph and 33 references are supplied. (Author abstract modified)