this work reveals a scale, with dicotonic questions, which has been created to detect psychopathic traits among the prison population. It was applied to 68 detainees in Atlacholoaya prison (Mexico), convicted of violent robbery, kidnapping, rape or homicide, who were also administered the MCMI-II (the external validation source) as well as two new questionnaires, with multiple choice questions, one focusing on the criminal acts committed and the other on family and social circumstances. The Atlacholoaya scale has confidence (according to Cronbach alpha) of 0,928 and a correlation (according to Spearman’s formulation) of 0,672 with the anti-social dimension of MCMI-II, in which it can be considered satisfactory, or rather promising, as a novel diagnostic test in the pilot phase.