[user104658]

Like I said it's a classic tale; conflict between sexuality and what "religion" tells people is morally right. Kids from birth are indoctrinated into believing the words of their religion - which tells them that homosexuality is wrong - and then they hit sexual maturity and realise that they are aroused by people of the same gender. But that religious doctrine is so firmly implanted that it leaves them with massive, illogical feelings of guilt and anger at themselves, which all too often results in them lashing out at other "sinners" in an effort to prove that they're "not like them".

Yes, this time it has been taken to a horrifying and devastating extreme... but there are countless examples of people in denial (of all religions) turning to violence, even murder, because of the fundamental incompatibilities between their instincts and their belief system. Most often it's the individual violent assault of (sometimes murder of) a person that they have felt themselves attracted to or who has perhaps indicated that they are attracted to them.

Let's not petend otherwise. Religion is a huge part of the problem. The other facilitating factor is the elephant in the room in the US... the far-too-easy access to high powered assault weaponry.