Homosexuals are also disproportionately represented among serial killers. Even though only about 2-3% of men are primarily or exclusively homosexual, it seems as though nearly half of the most notorious serial murderers had male victims (e.g. Gacy, Dahmer, Baumeister, Berdella, Corl etc).
So it's not surprising that there's a high level of cross-dressing, "transgender" delusions etc among killers as well. Richard Speck comes to mind as one.
Juan Corona killed at least a couple of dozen farm workers in California back in the 1970s. From the news reports it seemed that he had sex with them before killing them, so may have killed them to prevent them telling others that he was homosexual. But that is just my recollection from what was reported in the newspapers.
Then there were the 30-plus black boys killed in the Atlanta area. I don't remember the name of the person they caught but that would be another example.