Violent and aggressive behavior in prison is considered to be a constant problem in most penal institutions and it not only poses a threat to prison staff and fellow inmates, but is also a source of additional cost. An early identification of inmates who tend towards violent or ag-gressive behavior in prison should therefore be a central goal, in order to both protect the staff and other inmates from becoming victims of violent actions and to lower the overall costs of the penal system. Furthermore in-prison behavior is suspected to be good predictor of legal probation after release to the community. There is an ongoing debate concerning the useful-ness of actuarial risk assessment instruments in predicting intramural violence as studies on their predictive validity show mixed results. In this study the predictive validity of PCL-R, PCL:SV and the VRAG for different types of prison misconduct (violent and verbally violent infractions) was examined on a sample of 106 violent and sex offenders of the largest Swiss state penitentiary.

The relationship between physical violence and PCL-R score was not significant but the sum score did predict the occurrence of verbal aggression. For the PCL:SV and the VRAG similar results were found as there were significant effect sizes for verbal aggressive behavior of sex-ual offenders but not for violent offenders.

These results highlight the need for further research on the usefulness of risk assessment instrument in the prediction of intramural violence.