Jury instructions regarding expert witnesses in Washington are outlined in Washington’s Pattern Jury Instructions, Civil Rule 2.10. Wash. Prac. Pattern Jury Instr. Civil 2.10 (2013). This rule is not mandatory when there is expert testimony, but if requested by a party the court should read the instruction specifically pertaining to expert witnesses. Id. The instruction regarding expert witnesses instructs the jury to determine the weight and credibility that each expert’s testimony should be given by considering the expert’s “education, training, experience, knowledge, and ability.” Id. Further, the jury should consider each expert’s testimony in light of all the testimony presented in the trial when evaluating each expert’s opinions. Id. Lastly, the expert’s reasoning and sources used to form his opinions are important for the jury to consider when evaluating whether to believe expert testimony. Id.
