ORLANDO, Fla. -

It was Thursday, Dec. 11, 2008, and Chief Medical Examiner Dr. Jan Garavaglia was late for her plane.

VIDEO:

Then she got word that skeletal remains of a child had been found around the corner from the home of Casey Anthony, the young woman she knew had been indicted two months earlier in the death of Anthony?s missing 2-year-old daughter, Caylee.

Caylee was missing no more.

But, Garavaglia told Local 6 Thursday, she could not change her plans.

When she returned to her office Saturday, Dec. 13, Garavaglia took over the case from a relatively new hire, Dr. Garry Utz. ?I felt that Dr. Utz hadn?t been here that long and that I should go ahead and take it over,? she said.

So when Casey Anthony goes on trial in May, Dr. G. -- as she is known to viewers of a cable television series in which she stars -- will be the key witness who will tell jurors Caylee Anthony was the victim of homicide.

That?s just one of dozens of revelations uncovered by Local 6 in a review of hundreds of pages of depositions taken in the case of the State of Florida vs. Casey Anthony.

Anthony, 24, is charged with first-degree murder and aggravated child abuse in a case where the state is seeking the death penalty.

Local 6 has reviewed previously unreleased depositions of Garavaglia and others, revealing not only how prosecutors are preparing to use testimony to buttress their claim that Casey Anthony murdered her daughter, but also how the defense may challenge that testimony.

Garavaglia was questioned under oath in her Orange County offices for one hour, 19 minutes on Tuesday afternoon, Sept. 28, 2010.

Her primary interrogator: prominent defense attorney Cheney Mason, who -- at age 67 -- reminded Garavaglia at one point ?this is not my first rodeo.?

?Will you define homicide?? he asked.

?The death at the hands of another,? Garavaglia responded, then, when challenged, added, ?Forensically, hands or means ? I don?t know if hands -- maybe actions of another or neglect of another.?

Mason then suggests another possibility: ?Suppose this child drowned in the family swimming pool??

Whether that is a clue to a possible defense -- accidental death -- no one will say. The defense and the state have refused to comment to Local 6 on unreleased depositions.

Garavaglia also declined comment, though in the deposition, she is not buying the drowning theory.

?We get many cases like that where people are drowned and they always report them because they want them to survive. There?s a chance that you could resuscitate that person,? Garavaglia answered.

Left unsaid: Casey Anthony never reported her daughter missing.

Her mother, Cindy, did call police on July 15, 2008 -- 30 days after she had last seen her daughter and granddaughter alive. But she only did so after locating Casey at a boyfriend?s apartment and discovering Casey had been lying for weeks about her whereabouts and would not reveal where Caylee was.

While finding the manner of death a homicide, Garavaglia said the cause of death is undetermined. There is no evidence of trauma to the body and no traces of chloroform, valium or other drugs found in the remains.

?You just don?t know how it?s a homicide?? Mason asked.

?Correct, based on the circumstances,? Garavaglia responded.

Mason: ?And the circumstances are what you have been told by the detective or other law enforcement people??

Garavaglia: ?No. The circumstances are that a child, an ? almost 3-year-old child is found in a plastic bag, in a laundry bag, dumped in a field to rot with duct tape in the vicinity of the lower mandible,? or jaw.