Neri and Michael had to make sure that Fredo’s body would never be found. At the same time, they had to put on a great show of demanding that the authorities drag Lake Tahoe and otherwise spare no effort to find poor Fredo’s remains. How did they do it? And, what do you think Neri told the authorities about how Fredo disappeared without his being able to either rescue him or find his body?

Keep in mind that the boat they were in was close enough to shore that Michael (and, presumably, everyone else at the compound) heard the two shots.