What is the burden of establishing the defense of momentary possession of a controlled substance?

A defendant has the burden of establishing the defense by a preponderance of the evidence. (People v. Spry (1977) 58 Cal.App.4th 1345, 1369.) CALCRIM No. 2305 instructs on the defense of momentary possession of a controlled substance. That instruction informs the jury that if a defendant possessed the controlled substance for "a momentary or transitory period" in order to abandon, dispose of, or destroy the controlled substance, then possession was not illegal. The terms "momentary" and "transitory period" are not further defined in CALCRIM No. 2305 or elsewhere in the pattern jury instructions.

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