Investigators suspected that Traverso had been drinking after finding receipts from a Coconut Grove bar for three gin drinks.
But with no proof Traverso actually consumed the drinks — no blood testing could be done because of the delay in surrendering — prosecutors could not charge him with DUI manslaughter.
this is why penalties for hit-n-run, especially in cases of injury, death or significant property damage have to be at least as harsh as DUI penalties.
the differences between those penalties in many jurisdictions means that's it's better to take a chance on fleeing the scene than stick around and get charged with a DUI.
the law can't assume that someone was drunk without proper testing and all of that due-process stuff, but it can put in place penalties that make up the difference, and at least encourage people to stick around at the scene.
seriously, anyone leaving the scene of a crash that leaves someone dead or seriously injured should be banned from EVER holding a driving license. and of course the penalty for driving without a valid license should be having the vehicle confiscated and sold at auction.