The Ohio Shooter has been confirmed as Connor Betts, age 24 (source, source). More information continues to come out concerning him. However, one of the immediate things that one will notice is the pins on his shirt.
I looked into this, and it appears that the patch on his shirt, “Against All Gods”, was put out by the Black Craft Cult website, an online store that sells satanic clothing.
The website appears to have deleted any reference to this product.
More information is needed to get a clearer picture as to the particular course of events that transpired. However, it is clear that the person who committed this was definitely associating with nefarious elements, even if it was only the particular philosophy itself.