I think it would be really good actually of they recorded each criminal's sex and "gender identity" - if they claim to have one.
For people who do not believe in these stereotypes, the "gender identity" would be stated as "none" and their sex recorded accurately.
For people who are not trans but believe in such stereotypes so have a belief they are the same gender as their sex, both would be recorded and it is clear then that they match, and how the crime statistics by sex should be categorised.
For people who are trans they would record their sex (so that crime stats are accurate, the nonsensical idea that a woman can commit rape is no longer perpetuated, and they are placed in the correct sex-segregated prison) but they can also record their "gender identity" so that for example, if they are a transwoman, while in the male prison staff will know to refer to them as she/ her. This is so important to them that I presume they'd want that to continue in the prison environment.
Then we would, by filtering the data, have accurate statistics on how many self-declared trans criminals, and male and female non-trans criminals were committing which crimes, which is surely one of the key purposes of collecting data in the first place: to get a clear and objective picture of trends in crime and who is committing it.