Well, of course not.
For starters, where the cops Christian? How about polling the surrounding Pride marchers: Statistically speaking, you should run into more than a few Christians even among them. In this scenario, could you call them violent?
Sure, there are a few bad eggs among Christians. Christian are human, therefore there is bound to be some. If you are using this to categorize all Christians as violent, then do realize that many other religions like Islam are so far beyond the pale on this issue that you'd have to categorize them as all violent as well. Are you comfortable with that? Furthermore, what about looking at them not as Christian but as Americans (or Brits/French/whatever y'all are) or as similarly male: Under your logic, all people like them must be violent, right? Including people like you, so...are you violent?