The aim of this paper is to make a comparative study on serial killers from different countries and link them to one of the traditional seven deadly sins in the Judeo-Christian culture.

Firstly, it was necessary to define each different deadly sin and establish its behavioural correlate. This was achieved thanks to a questionnaire designed to measure the interrate agreement within a sample population. Once the categories were defined (pride, lust, envy, sloth, wrath, gluttony and greed), 30 serial killers from America and Europe were analyzed in order to determine the sin behind their motivation to commit a crime. The evaluation was based on the Coding Guide – Serial Killers Research Project – created by the unit of analysis of criminal behavioural (University of Salamanca, Spain). Afterwards, an ex post facto descriptive non experimental study was carried out to find out the relation between the serial killer's own characteristics and the deadly sin linked to their motivation.

The results show a clear predominance of pride, lust and greed as the main motivations within the study sample. As well as some possible dependency relations between killers’ motivations and some other variables, which could be helpful when applied to the offender profiling field like sex or personality.

The authors have not supplied their declaration of competing interest.