You are exactly correct.  I have no dog in this fight, but for this information to be considered scientifically meaningful you'd have to do some inferential statistics.  Looks like there's plenty of data to do an ANOVA or MANOVA to determine if the differences noted are "real" or just spurious.  I would also suggest that the study control for exogenous variables (as suggested by Mike C.) such as the nature of the offence the suspect was charged with.

I also think that the reporting on this issue fails to recognize many of the caveats explicitly stated in the report.  The reporting focuses on uncertain conclusions as if they were gospel.