Characteristics of mentally retarded criminal offenders in Northern Taiwan

The characteristics and criminal behavior in mentally retarded Individuals remain largely unstudied. This retrospective study sought to establish a se t of reference of criminal behavior characteristics in an ethnic Chinese me ntally retarded group. Data were collected from forensic psychiatric evalua tion of 32 mentally retarded offenders. Of the 32 offenders, only four (12. 5%) cases were female. Mean age at the time of the offenses was 31. By IQ t esting, 23 (71.9%) of the group fell into the mild mental retardation range , seven (21.9%) into the moderate mental retardation range, and two (6.2%) into the severe mental retardation range. Nineteen (59.3%) of the group als o suffered from additional mental disorder. Eight (25%) had definite neurol ogical deficit. Fourteen (43.8%) were repeat offenders. A total of 24 (75%) of the offenders had committed crimes against property, with 13 having com mitted petty theft. Furthermore, the pattern of offending shows differences from that of the general population or other mental disorders. The propert y offenses, especially petty theft and arson, were frequently seen. There w as no noteworthy above average frequency of sexual offenses.