A medical examiner is a physician who has undergone specific subspecialty training in the area of forensic pathology and medicolegal death investigation. 

The first step in becoming a Medical Examiner is the completion of medical school and receiving an M.D. or D.O. degree.

The second step is completing years of training in an accredited anatomic and/or clinical pathology residency program.  This training serves as a background in the study of pathology, or the examination of tissues and fluids to establish the diagnosis of disease processes.

The final step is a fellowship, a year of sub-specialty training specific to forensic pathology, tapered to the performance of autopsies to determine the cause and manner of death.  The fellowship year provides specific training in the diagnosis, interpretation, causation and consequences of injuries.  The training also includes diagnosing disease processes, interpreting laboratory and toxicology results and determining their contribution to the death of an individual.  

Following each step of the training process, a medical examiner must complete board certification examinations to demonstrate competency in the fields of pathology and forensic pathology.

Some jurisdictions outside of Utah function under the guidance of a coroner.  A coroner may or may not have any medical background or training and is elected or appointed to his/her position.  The coroner in those jurisdictions is responsible for certifying the cause and manner of death on a death certificate.

For more on this topic visit the NAME website.