A coroner is a public official who investigates deaths defined by law as being important to the public health and welfare. These generally include deaths thought to be from other than natural causes but also may include sudden and unexpected deaths determined later at autopsy to be from natural disease.
In general, coroners are elected and, depending on the local law, do not necessarily have to be medical doctors or other health professionals. But only medical doctors can perform autopsies.
WebMD Medical Reference from Healthwise