Investigation is the process of gathering information about an accident, the resulting harm, possible legal liability of any party for having caused that harm, and potential sources of restorative payments owed to or collectible from others to finance recovery from that harm.
You may call them simply doctors. But most doctors have extra expertise in one type of medicine or another. In fact, there are several hundred medical specialties and subspecialties. Here are the most common types of doctors you'll likely see.