Not most, but about 1/3, and when you consider they're about 2% of the population, it's incredible how over represented they are.
I got my "most" figure from going through a list of serial killers and seeing how many were homosexual. Of all the ones listed, the homosexuals constituted a majority.
Am willing to look at another source that is better researched. But yes, they are way over-represented among both serial killers and child molesters.
Also, their crimes tend to be exceptionally vicious and debauched. They don't just stab someone. They stab them 50 times and try to cut off their head. They also like torturing their victims.