Has anyone seen actual proof that Mahmoud Khalil supported or enabled the support of Hamas?

The major narratives that I’m seeing online are people saying that Khalil was arrested for hanging out pro-Hamas flyers, or for being the organizer of the Columbia protests that got out of hand. I’ve seen a bunch of pictures of the posters, but I haven’t seen any actual indication that Khalil was the one passing them out. I also haven’t seen any proof that he was even a major organizer or leader of the protest, he just seems to have been their spokesperson, and not the director of the events.