In this case, the trial court -- Michael Knish, a temporary judge in San Bernardino -- didn't do that, and instead gave a lengthy series of examples to the jury about what wouldn't constitute "reasonable" doubt. He started out by saying that even though the jury couldn't see all of the American flag behind him, since it was creased in various places, and hence it's possible that the flag had the judge's face on it or something, any doubt about whether this was indeed an American flag wouldn't be "reasonable". He then says that if there was a jigsaw puzzle that looked like President Obama, but was missing a piece of his forehead, a piece for his chin, and a piece for one of his ears, any doubt that it was indeed President Obama similarly wouldn't be reasonable despite the missing pieces. He finally said that if the jury was planning a party or something in San Bernardino in August at noontime, any doubt as to whether it would be higher than 50 degrees at that point wouldn't be reasonable.
Not exactly the "Let it be" traditionally expected by the Court of Appeal.
It's even worse than this. There's a Court of Appeal case from 2009 that involved nearly an identical "explanation" in which the trial court similarly tried to explain reasonable doubt by reference to a jigsaw puzzle of the Statute of Liberty with six pieces but two pieces missing -- the face and the upper left corner. Reversed. Can't do that.
Plus, here, it's arguably even worse. The big issue at trial is the judge's reasonable doubt instruction. The defense counsel makes this issue a central point of his argument (since he's got, as in many cases, very little else to go on). Saying that the judge was wrong about what counts as reasonable doubt, making arguments based on the judge's "American flag" analogy (claiming that he's actually snipped off a star), etc. (Ignore for a moment whether it's a really effective defense strategy to take on the judge.) The prosecution also makes a big deal about this stuff, saying that the defense is wrong, the judge is right, the law is what the judge tells 'em it is, etc. So this is a central part of the trial.
So what does the Court of Appeal do?
It's a 2-1 vote. With Justice Ramirez writing the majority opinion and Justice Miller dissenting.
See who you agree with. And whether the trial court -- and/or the Court of Appeal -- should indeed have Let It Be.