Bimodal distribution of violent assaults

The aim of the present study was to investigate the relationship between the number of injuries inflicted on victim during violent assault and other variables, characterizing the offender and the assault. The study is based on all the cases that were processed at the City Court of Tallinn, Estonia in 1986 and 1996. The number of assault-related injuries caused to the victim in Tallinn, Estonia, for 1986 and 1996 revealed bimodal distribution. About 2/3 of the assaults resulted in 1-5 injuries, in 1/3 of the cases the number of inflicted injuries was 10 or higher, with only a relatively small number of injuries in between. This distribution pattern was stable over the 10-year interval between the observations and was invariant to alcohol intoxication, consequences, and reasons for the assault. Comparison of the offenders' criminal record during the 15-year follow-up period showed that recidivism was more common among those who had committed a multi-injury assault as their first offence. The evident distribution of assaults into few- and multi-injury groups and the fact that the number of injuries caused during the first offence is a more reliable criterion for predicting the further criminal record of the offender than the consequences of the assault suggest that there are two discrete types of behaviour determined by a set of variables characteristic of the offender's psychology.