This investigation dealt with the identification of a special category of killer referred to here as the cold blooded killer personality. The purpose was to identify certain personality traits that might distinguish this killer from a normal control group, softcore inmates, hardcore
inmates, a random sample of inmates, and assaultive inmates. Significant differences were found among five groups of incarcerated felons and a normal control group in terms of certain personality traits and significant test items. Multivariate analysis of variance revealed a significant main
effect between the groups. Univariate F ratios were significantly different for twelve of the thirteen MMPI subscales. Simple effects analyses using the Duncan with a .05 level of confidence reliably discriminated between a number of group comparisons. The subjects were young adult males matched
for age, sex, race and certain socioeconomic variables.