We dont know if the shooter was a groyper. Its still worth pointing out though, groypers specifically had a feud against Charlie Kirk. They are ultra-right white nationalist who are harshly critical of more mainstream right wing people they consider to be not far enough to the right or not nationalistic enough. Their leader is Nick Fuentes and he had some kind of falling out with Charlie Kirk and directed his Groyper army to show up to Kirks events and harass him.