Thats one part that bothers me... Why does he has a profile?
I would assume he would kill only men of relatively old age (because of his father I guess). But men at their 20s and women at their 30s? Does that ages have any meaning?
No, he killed people that he could overpower and couldnt track to him since that was pre-digital age so all they had were a missing person case.
Plus we clearly seen at least a women as one of his victims, he simply picked on people that he picked up late at night without witnesses and apparently lived alone, their age and gender was not relevant ... only that those people wouldnt be traced back to him.
If you want a profile, there is Alexei Ivanov but in this case, he just did it out of convenience.