I wonder what underlies incinerating these people means. If the three deceased are the Florida trio... and if it was a drug related event. One reads/hears of many drug related killings... shootings, beating, whatever... but to fully incinerate the bodies. Is this commonplace for something like this? Maybe it is.
Here's an off-the-cuff fully speculative 'could be'... What if the three deceased are not the Florida trio. What if they are entirely other people. What if the Florida trio murdered three unrelated persons and incinerated them hoping for no identification possible... so that the general thinking would be it was the Florida trio. This may have been thought to be an opportunity for the Florida trio to "vanish." Kinda wild (and made-for-TV-movie-ish), I know.