Both things are true. The research shows biological men have a certain level of increased criminality, sexual assault perpertration, and offending relative to natal women (who in addition to being the most common target for sexual violence are much weaker physically), and that this appears to be unaffected by gender identity. This should be obvious on the face of it, but they have done studies nonetheless, including looking at a post gender-affirmation surgery cohort.
This group is few in number, but the self-ID gender as a ticket into sex-segregated spaces policies they advocate for throws the door open to all men, increasing the risk to women substantially. I’m not saying a transwoman poses a risk greater than the average male who doesn’t identify as a woman. Nor that all, or even most, men are violent. And I’m not saying that transwomen are a hundred percent safe in male prisons, which is why special provisions are made for them within (rather than prioritising their safety above half of humanity by ignoring the physical and statistical realities of life).
None of this is contradicted by the observation that black transwomen engaged in prostitution have a higher risk of being a victim of homicide than the general population (though lower than that of a female prostitute). Or that men have killed transwomen when they realise they were “duped” and respond with fatal homophobia (sex attraction is based on biological sex, hence the reaction that would not exist otherwise). Atrocious, but this has nothing to do with women, redefining them to spare anyone’s feelings, or as a way of justifying access to their spaces.
Having said this, all people deserve respect, regardless of gender expression.