The paper aims at studying pro-social preferences among subjects with and without a record of illegal behaviour, with respect to their Psychopathy levels and their behavioural patterns in the Trust and the Corruption games. The basic hypothesis of our experiment is that people with a record of illegal activity have a preference for pro-social outcomes, similar to that observed among non-institutionalised subjects. To this effect, we compare our findings to a control population of subjects without a record for illegal actions. So far, the experimental literature on Psychopathy, Trust and Corruption has focused on the study of the usual student subject pools. The major innovation of this study is that it obtains evidence of the pro-social component of human behaviour in the presence of a monetary temptation among a population of institutionalized subjects within prison. Prominent among our results is that prisoners demonstrate higher levels of Trust and a more prosocial behaviour in the Corruption game than the non-institutionalised subjects. Further, Psychopathy levels in the trust game is only significant and negatively correlated to reciprocity by player 2 for the non-institutionalised subjects. In the Corruption Game higher Psychopathy levels are connected to less prosocial behaviour by institutionalised subjects. Establishing differences and similarities on ethical behavioural patterns among normal and institutionalized subjects is a matter of major importance for rehabilitation programs and the overall process of reinsertion of convicted persons to the society.