Not much forensics necessary, he got shot is pretty easy. Not much refrigeration there either, which is why corpses hit the dirt in one day in the Middle East. When you do not do the embalming thing, you don't exactly want to have the body lay around in the living room for a week.
He was flown back to Italy for the funeral. If they didn't autopsy, that's prima facie evidence of a cover up. Autopsies are routine. A couple of hours and then you have all the samples you need to investigate as thoroughly as you want. Autopsy is also necessary to ensure that the cause of death is the same as what you THINK the cause of death is.