Do we know it (her death) involved duct tape?
Or do we really just know it was put there?
Make no mistake, Dr. G is an incredible ME and honest as the day is long. However, she has never said that the duct tape caused the death - because medically she has been unable to determine the cause of death. Nor has she ever said who killed Caylee.
What a lot of people don't understand about a medical examiner is that they do not approach their role from only a medical science standpoint, rather they approach their role from a social sciences standpoint. The combination of the two fields is forensic science.
So when she makes a statement that the manner of death was homicide, she is simply saying that based on not just her autopsy (which involves medical science), but the law enforcement reports and collateral circumstances surrounding the person's death (which involve social science), that it is safe to say X-individual died as a result of another person's hands. Which is homicide.
And not to oversimplify, it does not take a ME to figure out that Caylee died at the hands of another by putting three simple facts together.
- Casey said Caylee had been kidnapped
- Caylee was found dead
- She was found concealed in a laundry bag in the woods (and yes, duct tape was around the head.)
These three facts rule out the possibility of a natural death and strongly point to another person being involved in the death - thus a homicide.
However, her finding does not preclude an accidental death, it only says the surrounding facts support a homicidal death.
Now a homicide is a forensic determination and murder is a legal determination. So Dr. G. is not going to be allowed to testify that I think a murder occurred. She will only be allowed to testify to her medical findings and then the state will present its other evidence and ask the jury to find that a murder occurred.
For those web sleuths out there who want a simple to read yet thorough book on forensics, I recommend you buy Forensics, a guide for writers, by D.P. Lyle, M.D.