Just as we want men who claim to be trans kept out of women's spaces =/= saying they are all rapists, saying that if a transperson who carries out a despicable crime =/= claiming they are all psychotic killers.
The fact they claimed to be trans may be pertinent. It is often a symptom of other mental health problems which seem to go untreated once 'stunning and brave' is, for want of a better word, diagnosed.
In this instance, whatever was wrong with the guy his anger was directed outwards before he turned it on himself. Suicidality though seems to be common in young transpeople; thought about, planned, attempted or realised.
What, once you've got your diagnosis, you don't feel stunning or brave? What, no matter how affirming your family or community is, you still feel alone and scared? What if you're not delusional enough to realise you don't pass? What if you can see on the faces of your neighbours, and children, especially, make bad liars.
If he hadn't committed such a vile crime I'd feel sorry for him.