I have to agree with the statement that it's not fair to assume a Christian did this. Anyone could have done it. Just because it looks like a Christian done it, doesn't mean a Christian did do it. The person who did this could want you to think that a Christian is responsible.

If a Christian church was vandalized with pentacles and hate messages, I would not assume a Pegan is responsible.

Sometimes, people do things just to be... horrible. I don't think it's fair to blame the Christian religion when anyone could've done it. Once it's proven to be someone "acting in the name of Christ," I'll be right there with you. They should be punished. It should not be overlooked. Hate crimes are unacceptable. For that matter, all crimes are unacceptable.