Why is that good news? Because we are far more likely to get accurate and truthful information from Trayvon Martin's autopsy than if Florida had a County Coroner system. Even after death, Trayvon has an ally in the Forensic Pathologist.
What's the difference between a Medical Examiner and a County Coroner?
The answer lies below the orange squiggle.
The Medical Examiner is a physician--an M.D. generally trained in the specialty of Pathology. These doc's usually go on to sub-specialty training in Forensic (i.e. legal) Pathology.
In that sub-specialty, they learn things like how to determine the exact cause of death, and to estimate accurately when the deceased passed away. They learn how to tell the difference between entrance wounds and exit wounds, and how to tell if injuries happened to the body before or after death.
To answer those questions, they have medical knowledge, the ability to look at tissues under the microscope, do chemical analysis of tissues and body fluids, do X-Ray examination of the remains (MRI's too). For example, imagine a case where a body is found in a partly burned house. How would one decide whether the victim fell asleep while smoking in bed and immolated themselves, or if they were strangled to death, and then the house set on fire to cover up the crime?
Medical and scientific expertise, is mandatory when big questions of life and death must be answered.
On the other hand, the County Coroner is usually an elected official. And even worse, may not be required to have any medical knowledge or be a physician. In fact, these positions are often filled by someone who is well-liked and politically connected--possibly the local mortician. (Hey, they have the right kind of vehicle to move the body, and they aren't scared of dead people!)
So you might wonder how an under-educated, elected official is going to decide whether someone was murdered or died of natural causes. You might wonder if their decision could be swayed by the politics of the situation, or their connections with the decedent or those who might have killed him/her?
I'm sure some County Coroners are good people. However, for the sake of truth and justice, it makes as much sense for the Coroner to decide what and who killed somebody as it would for some other elected official to remove your gall bladder.
So, hooray for the Florida Medical Examiner System. May the truth be told.