<< At any rate,I am curious about florida juvanial law as it pertains to how long the child can be behind bars. >>
In many (most?) states, there is a limited category of children in which they can be tried as adults if the crime was so awful as to warrant such a finding (ie., the assumption is that they were acting like adults since the crime is so horrible -- no child would commit it). Something like that, at any rate. I think it can be as low as 10 years old, but I know that 13 year olds qualify in many jurisdictions.
So, while the age of the perp in this case was normally within juvenile limits, he was tried as an adult and received an adult sentence. I think they put these kids in juvenile detention until they reach maturity then throw them in the big house.