[JoeRedskin]

Here's the Florida pattern jury instructions on the issue:

A person is justified in using deadly force if he reasonably believes that such force is necessary to prevent, one, imminent death or great bodily harm to himself or another, or, two, the imminent commission of aggravated battery against himself or another.

* * *

If in your consideration of the issue of self-defense, you have a reasonable doubt on the question of whether the defendant was justified in the use of deadly force, you should find the defendant not guilty. However, if from the evidence you are convinced that the defendant was not justified in the use of deadly force, you should find him guilty if all the elements of the charge have been proved.

The defendant has entered a plea of not guilty. This means you must presume or believe the defendant is innocent. The presumption stays with the defendant, as to each material allegation in the information, through each stage of the trial unless it has been overcome by the evidence to the exclusion of and beyond a reasonable doubt. To overcome the defendant's presumption of innocence, the State has the burden of proving the crime with which the defendant is charged was committed and the defendant is the person who committed the crime. The defendant is not required to present evidence or prove anything.

emphasis mine.