What were these reporters doing in the hour prior to the arrest? Oh, nothing? Well, where were they at the start of the riots? Just getting to the scene? Hmm well, what's the police officer's story; has he had bad experiences with the press in the past? And so on...
Most people have seen enough coverage of police officers doing unreasonable things in order to make a judgement call based off the provided context here. By asking for even more context, it comes across as though you're trying to cast doubt on this situation and undermine what's honestly a national issue at this point - hence the downvotes.