Apparently, in FL you can shoot and kill anybody walking down the street,

[spin]

43. The main difference between the newer version of the law...

named 'Stand Your Ground' and the previous law is that if a person is attacked in a manner that has reason to believe will result in serious injury or death, he no longer has a duty to retreat.

Merely being threatened often does not justify the use of lethal force. It didn't before and it doesn't now. If the attacker is armed or if there is a large disparity in size, physical condition or age the use of lethal force might be considered appropriate.

Use of Deadly Force for Lawful Self-Defense

***snip***

Q. When can I use my handgun to protect myself?

A. Florida law justifies use of deadly force when you are:

Trying to protect yourself or another person from death or serious bodily harm;
Trying to prevent a forcible felony, such as rape, robbery, burglary or kidnapping.

Using or displaying a handgun in any other circumstances could result in your conviction for crimes such as improper exhibition of a firearm, manslaughter, or worse.

Example of the kind of attack that will not justify defending yourself with deadly force: Two neighbors got into a fight, and one of them tried to hit the other by swinging a garden hose. The neighbor who was being attacked with the hose shot the other in the chest. The court upheld his conviction for aggravated battery with a firearm, because an attack with a garden hose is not the kind of violent assault that justifies responding with deadly force.
http://licgweb.doacs.state.fl.us/weapons/self_defense.html

The web page also mentions that if a person uses threatening language, that alone does not justify the use of lethal force even if the threats cause you to fear for your life. You have to have a "reasonable" belief that the other person will severely injure or kill you unless you take "immediate action."

If there is any question if you acted properly it is quite possible you will be prosecuted and a jury might determine your fate.