AOC isn't exactly wrong. We've had this occur in my country just a few months ago.

There was a mass stabbing in England where three children were killed. False claims that the attacker was a Muslim asylum seeker spread online and led to white supremacist riots across the country. The suspect (later named because the court lifted an anonymity order) was later revealed to actually be a British born teenager with Rwandan parents. He wasn't even a Muslim.