MBE Rules · Evidence

Expert Opinion Basis

FRE 703

The rule

An expert may rely on inadmissible facts if experts in the field reasonably rely on such data, but the inadmissible basis may be disclosed to the jury only if its probative value in evaluating the opinion substantially outweighs prejudice.

In plain English

Experts can use information that isn't normally allowed in court if it's something that other experts in their field would reasonably consider. However, if this information is shared with the jury, it must be shown that its usefulness in understanding the expert's opinion is much greater than any potential harm it could cause.

Worked example

In a medical malpractice case, a doctor testifies as an expert and relies on a study that was not admitted into evidence. The jury is informed of the study only after the court determines that the study's relevance to the doctor's opinion significantly outweighs any negative impact it might have on the case. As a result, the jury can consider the study when evaluating the doctor's testimony.

Memory hook

Experts can use the 'inadmissible' if it's 'reasonable'!

The trap

Exams may present scenarios where students mistakenly believe that any reliance on inadmissible facts automatically disqualifies the expert's opinion, overlooking the reasonableness standard.

How examiners test it

Questions often involve a hypothetical expert witness who relies on inadmissible information, testing the candidate's understanding of when such reliance is permissible and how it should be disclosed to the jury.

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