Not really, but this seems more like projection to me.
There is only thing I know for sure and it's that the shooter wasn't a leftist. There is nothing about him that suggests him being a leftist, and certainly nothing that would suggest he's been radicalized to the point of a targeted killing by the left. The only thing you have to go on is what the state and federal investigators say they have, which they obtained through a source they didn't name.