205a            EXPERT TESTIMONY: HYPOTHETICAL QUESTION (Questions Asked by both Prosecution and Defense)


During the trial, an expert witness was told to assume that certain facts were true and then was asked for an opinion based upon those assumptions. This is called a hypothetical question.

As to the prosecution's case an opinion should be considered only to the extent that the assumed facts upon which it is based are true and correct. Such an opinion does not establish the truth of the facts upon which it is based. As to opinions favorable to the prosecution, unless you find that the facts stated in the hypothetical question have been proved beyond a reasonable doubt, you must not give any weight to the expertís opinion in favor of the government when that opinion is based on those unproven facts.

Because the burden of proof never shifts to the accused and you may not convict the accused if you have any reasonable doubt as to his guilt, the prosecution must prove the facts beyond a reasonable doubt. Therefore, you may give weight to an expert opinion favorable to the accused if you have any reasonable doubt as to the facts that form the basis of that opinion in favor of the accused. That is, you may give weight to an opinion from the expert which is favorable to the accused unless you find that the prosecution has proven beyond a reasonable doubt that the facts upon which the opinion is based are not true. That opinion, by itself, may then give rise to a reasonable doubt in your minds.


NOTE: This is not (yet) an official instruction. It was drafted in response to an allegation of ineffective assistance of counsel because counsel allowed the official instruction 205 to be given to the jury when a defense rested on answers to hypothetical questions. It was the position of appellate counsel that the standard instruction shifted the burden of proof to the defense. Trial counsel (your webmaster) agreed.

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This page last updated on Wednesday 15 December 2010 .