Who's in control at various scenes has caused no end of trouble. There is what NIMS says (which is supposed to be federal law - hahaha - I'm funny sometimes), there is what is real. Want to have fun? Watch FDNY and NYPD try to decide that, when it's a possible crime scene, along with a technical rescue, where the FDNY Rescue units and ESU are both on scene. It's come to blows in the past