See how admitting you killed someone shifts the burden of proof in self defense to the accused?
It is for the prosecution to prove or not prove it's charge. It is not for the defense to prove jack shit.
Actually , CG, Save has a point here. Self defense is what is called an "affirmative defense", which simply means the burden of proof in asserting that defense is on the defendant; BUT, (and this is critical), the standard of proof required of the defendant is NOT "beyond a reasonable doubt", but simply the "preponderance of the evidence"; that is, if the greater weight of evidence favors the defendant's affirmative defense (however slightly), it must be presumed to be so; the burden on the defense is not to prove, but to simply tip the scale. This is not a trivial distinction. Further, the defense will have the opportunity, under this Florida statute, to present a motion for dismissal of the murder charge if it can show to the satisfaction of the judge presiding that the preponderance of the evidence indicates self defense. The judge may so find, and dismiss the case, or leave the finding to a jury.
The real worm in the apple here may be the current Florida self defense statute; its wording would suggest that a use of deadly force is self defense, provided only that the defending party was not where he was unlawfully, did not commit an "unlawful act" prior to whatever "unlawful act" by the other party led to the use of deadly force, and that the force was used in "reasonable" fear of death, OR "serious bodily injury". To overcome "the preponderance of evidence" affirmation by the defendant, the state would thus have to show either that he (a) violated some Florida statute prior to the "unlawful act" of the other, or (b) that his fear of death or serious injury was not "reasonable" under the circumstances. The overall effect, as I interpret it, is to create a fairly low bar for the defense to clear to establish self defense; it appears in this case it would be sufficient simply to show no violation of Florida law in the incident, up to the use of deadly force, and that his fear of death or serious injury was reasonable, by the standard of common sense. A showing that the other party's conduct was a felony under statute, would be sufficient to establish the latter point, so it is entirely possible that the Florida statute on "aggravated battery" might also come into play; it's not hard to imagine the defense asserting it in this case.
All that is somewhat confusing, but I think we may very well be confronted with exactly that sort of confusion with regard to the application of law in this case.