Anti-semitism being possible, akin to the racial hate crime shooting in the Buffalo, NY, shopping market. JTA links here and here.
However, while the community has an above-average Jewish segment, reporting per CNN suggest motive was unclear, and that it was a troubled family.
Web search links, here and here. One wonders how the NRA will rationalize how this individual attained ownership of multiple firearms. He reportedly passed background checks. It seems Highland Park's above average Jewish population might be a coincidence. Reporting is the shooter contemplated a second same day mass shooting in Madison, WI. He did the crime where he had grown up.
UPDATE: ADL reporting "debunking" multiple "false narratives" about the gunman. Read the item. It is not a normal human doing such a thing, but speculative misinformation about his abnormality as in some way political should be avoided. Unless and until reliable news surfaces. (As to reliability, the ADL item notes MTG having uninformed speculations she is all too eager to share. A/k/a super unreliable.)