Are you seriously advocating that we be allowed to kill someone, claim self defense and then be allowed to go free until it's proven that our claim is false? Has there ever been another example of this happening?
Guilt is decided at the trial, not the arrest. Killing someone should always be probable cause that a crime has occurred.
It's a fairly controversial law:
http://www.tampabay.com/news/publicsafety/crime/article1128317.ece
For the first half of this decade, the state counted an average of 34 justifiable homicides a year, as few as 31 and as many as 43.
That continued in 2006, the law's first full year.
But the next three years brought these numbers:
2007: 102.
2008: 93.
2009: 105.
The first six months of 2010: 44.