Refer to you incident or triage commander. Our protocol in Maryland is using any free personnel to manage them, assuming they don't have any life-threatening injuries. The goal should be to keep them out of harm's way and keep them from being disruptive, so it's a task you can delegate to almost anyone as long as they aren't quick to do something dumb (so I prefer to task EMTs or firefighters before cops). In an ideal scenario commanders will be aware of any personnel with media or mental health training and assign them to help with people who struggle in that particular fashion.