I'm not sure I follow your argument here. Are you for or against the anti-discrimination law as it currently is or do you feel it should be amended? 

Serial killers and pedophiles are not, nor should be, a protected class as their actions are consensual. A murder victim does not consent to having his or her life taken. The victim of child sex abuse does not consent to that activity. Two adult men or women choosing to engage in consensual acts of love and, yes, sex, should not mean that they are held as second class citizens, just as someone's skin color should not. 

I realize there is an argument that one can choose one's sexuality while one cannot choose race. Though I lean, personally, towards sexuality not being a choice.