I don't think it's a gender issue, per se, but one of power/dominance. (Sexual assault is about power, not about lust.) In either case, abusers were attracted to easy prey. I think the question is really what can people do in order to better screen people working with people with disabilities or people with mental illnesses.

And sexual assault can happen between members of the same sex. Women can also assault men--Mary Kay Letourneau, anyone?