Of the tools that we use, number one is communication. This is in any event, regardless of whether it's a one-on-one contact between a police officer and an individual or a riot situation. If you are at a point where you have to resort to batons, weapons, or tear gas, then that communication has broken down and it's not as successful.
The communication we speak of is one where we would, prior to the event, impress upon all the participants who are planning to be there that it's necessary for them not to wear a mask at the time. That simply reduces the number of people who are masked. Then when it comes to the point of trying to identify who has committed the criminal acts it's a lot easier to get those people identified, arrested, and off the street. Hopefully that will reduce the amount of rioting and will renew the ability of peaceful protests to be heard.