This Media Matters article discusses the topic of transgendered individuals (or non-transgendered individuals pretending to be one) committing sexual assaults in public restrooms.
They interviewed a number of experts on the topic, and none of them were aware of any case of such sexual assaults occurring. A selection of the interviews are listed below:
In an email to Media Matters, Jim O'Neill, legislative liaison and
spokesman for the Connecticut Commission on Human Rights in
Opportunities, reported no problems as a result of the state's
I am unaware of any sexual assault as the result of the CT gender identity or expression law. I'm pretty sure it would have come to our
attention. [Email exchange, 3/6/14]
William Hoshijo, executive director of the Hawaii Civil Rights
Commission, told Media Matters in an email:
In Hawai`i, the protection against discrimination in public accommodations on the basis of sex, including gender identity or
expression, has not resulted in increase sexual assault or rape in
women's restrooms. The HCRC is not aware of any incidents of sexual
assault or rape causally related or attributed to the prohibition
against discrimination on the basis of gender identity or expression.
Des Moines Police Department: "We Have Not Seen That." In an
interview with Media Matters, Des Moines Police Department spokesman
Jason Halifax stated that he hadn't seen cases of sexual assault
related to the state's non-discrimination ordinance:
We have not seen that. I doubt that's gonna encourage the behavior. If the behavior's there, [sexual predators are] gonna behave
as they're gonna behave no matter what the laws are.
Considering that a wide range of subject matter experts such as police officers and civil rights commissioners have not heard of any such incidents across the country despite the highly inflammatory and newsworthy nature of any such events, it is highly likely that no cases of sexual assault by transgendered individuals in public restrooms have ever occurred.