What's funny is that if a foreigner had made those accusations against an American police force, half of Mudcat would assume they were *obviously* true. No further investigation needed!

If A & R are guilty, then a pair of perfectly normal appearing college kids decided to murder the roommate of one of them, for no particular reason, right there in the house. The fact that a known drug-dealer and drifter has been proved scientifically to be the killer (or at least "a" killer) apparently doesn't matter. A & R then somehow mopped up all their own DNA from the crime scene, carefully leaving the other DNA, blood, etc., intact. Then, instead of dumping the "murder knife" into the river, they placed it in Rafael's kitchen.   

I don't claim to know just what happened, but I'll take the opinion of the independent DNA analysts, the Italian appeals jury, and the two judges who were part of it, over that kind of conjecture any time.