"Mountain of Evidence"

It's a reasonable metaphor for a criminal case. The law speaks to the "weight" of the evidence and mountains seem to weigh a lot. But it is not quite, or not just, that. A charging document can be evaluated as a sort of equation. The prosecutor proves the elements of the crime and this+that+the other thing=guilty. Both the weight and the arithmetic analogies leave out "quality". A mountain of feathers does not weigh the same as a mountain or granite. The quality of the construction matters. If a prosecutor ticks all the boxes in the equation (s)he may still get 2+2=5 if the jury thinks he has just ticked and not hammered beyond a reasonable doubt the boxes. Commentators, legal and lay, also often speak of a "strong" or a "weak" prosecution case. That gets more to quality. I am reminded of a metaphor used in a completely different, non-legal, context: "Ten cups of weak coffee do not yield a pot of strong coffee". (Yes, the Ivory-billed woodpecker really is extinct).