You're Just Asking Questions™ eh? Alright I'll bite, mainly for anyone else coming through.

Firstly, so much of the world is actively hostile to trans people that trying to use it as a defense would backfire in the vast majority of courts. The trans panic defense is unfortunately a very real thing that lets killers and rapists get away with heinous crimes. A recent example of this is in Tennessee, where a court overturned a murder conviction upon finding out that the VICTIM was trans, as if that somehow makes it ok - news article.

Secondly, assuming said strawman does make it to a court where they have to plead, under oath, that they are trans and should be sent to a women's prison, and that argument doesn't backfire- the court is going to want to see hard evidence for this claim. A random cis dude claiming to be a woman is very unlikely to have any kind of evidence to show.

Sidebar, I don't think you understand how much emotional and physical labor (and money) is actually involved in transition. Just getting approval for HRT is usually a huge ask, with people sometimes waiting years for approval, and that's just the first step. Mind you this is not an argument for transmedicalism- there are trans people who don't seek the medical route but are still valid. Such a theoretical case would be exceedingly rare and require a level of nuance and scrutiny that I have zero faith the courts can provide, but even then an actual trans person is likely to have a recorded history of dysphoria, social transition, or a name change. It really is not feasible to just "identify as a woman" overnight, and implying as such shows a complete lack of understanding

Finally, it's worth mentioning that trans people are overwhelmingly more likely to be the victims of violent crime rather than the ones committing it - source

I find it particularly interesting that you assume being in the US would benefit you as it's literally heading towards a trans genocide. Fwiw, I fled the US a while ago when I saw the writing on the wall.

Please take some time to meet actual trans people and talk to us, rather than resorting to strawmen