I read his screed.
Whether and what I blame is of no consequence.
The perp blamed the Aspberger’s. HE killed because he thought his father should not have reproduced while knowing he (his father) knew that it was possible that his children might have it.
You can claim that it was ‘liberalism’, but that’s not what the perp thought it was.
The perp's "thoughts" didn't get there by themselves....he obviously learned a lot of America hating from somewhere.