Canada

In Europe, its not uncommon for nurses and paramedics to volunteer on weekend nights around cities, primarily to supplement the underfunded and understaffed ambulance service by patrolling with a first aid kit and defibrillator since it gets easy credits towards their degrees. While there is a working relationship with Police, its pretty established in those roles that keeping the cops at a bit of a distance tends to be for the better. If you have the cops about, people tend to lie more and get worse care because of it. They also tend to consent less. I'm not saying incidents don't happen, but having cops about causes more of then than it prevents.

someone trained in protecting

I don't know that I've ever seen a cop protecting anything other than a storefront

Okay so send them with another nurse or some security.

Security officers are wayyy different from cops.