The accused was charged with a series of sexual assaults on 2 male children. He tendere the evidnece of a psychiartist to establish that in all probability a serious sexual deviand had inflicted the abuse, including anal intercourse, and no such deviant personality triats were disclosed by the accused in various tests including penile plethysmography.

After a voir dire, the trial judge excluded the expert evidence becasue it purported to sho only lack of general disposition and was not saved by the "distinctive group" exception recognized in Mohan.