I'm pleased that there is finally some level of pushback against the violence that these men spout. We see it all the time and have done for years on their signs at protests, in their tweets. And I think society (and the police) dismissed it as harmless "righteous anger", noone who likes gay people and "being kind" would ever actually hurt someone just because they disagreed with them, right??
But now someone has gotten hurt, murdered, and there's bound to be fallout from that. The guy who murdered her probably didn't come up with his hatred by himself, it was fed into by the violent rhetoric women have been complaining about for years. Maybe now the police will start to take it more seriously.
Do this guys posts cross the line into criminality? I don't know. But I think the threshold for "their side" has lowered a few pegs to get closer to the rest of us.
I don't think there's any real suggestion he knew that she was murdered? The dying painfully comment is just general inhumane horribleness and the chained to the bed comment is, I believe, in reference to female prisoners being shackled while they give birth.