What is the test for admitting a witness who has admitted that they have no memory of the event?

"Normally, the testimony of a witness that he or she does not remember an event is not inconsistent with that witness's prior statement describing the event. [Citation.] However, courts do not apply this rule mechanically. 'Inconsistency in effect, rather than contradiction in express terms, is the test for admitting a witness' prior statement [citation], and the same principle governs the case of the forgetful witness.' [Citation.] . . . "As long as there is a reasonable basis in the record for concluding that the witness's 'I don't remember' statements are evasive and untruthful, admission of his or her prior statements is proper. [Citation.]" (People v. Johnson (1992) 3 Cal.4th 1183,

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