Two studies focused on why attitudes toward the death penalty are consistently predictive of jurors' verdicts in criminal trials. In the first study, 36 eligible jurors viewed a videotape showing conflicting testimony by prosecution and defense witnesses in an assault case. Death-qualified subjects interpreted testimony in a manner more favorable to the prosecution than did excludable subjects, suggesting that differing interpretations of evidence may mediate the relationship between attitudes toward the death penalty and verdicts. In the second study, the same jurors indicated their reactions to a number of hypothetical situations in which a jury had convicted an innocent defendant or acquitted a guilty one. Death-qualified subjects expressed less regret concerning erroneous convictions and more regret concerning erroneous acquittals than did excludable subjects. Theoretical interpretations of this pattern of results suggest that death-qualified subjects may have a lower threshold of conviction than do excludable subjects; thus the relationship between attitudes toward the death penalty and verdicts may also be affected by differing thresholds of conviction. Footnotes, reference notes, and a list of 47 references are supplied. (Author abstract modified)