What is the test for a motion to exclude a defendant's statements from a sexual assault trial?

threats or violence, obtained by direct or implied promises, or secured by the exertion of improper influence. . . .' [Citation.]" (People v. McWhorter (2009) 47 Cal.4th 318, 346-347.)

"To demonstrate ineffective assistance of counsel, a defendant must show that counsel's action was, objectively considered, both deficient under prevailing professional norms and prejudicial. [Citation.] To establish prejudice, a defendant must show a reasonable probability that, but for counsel's failings, the result of the proceeding would have been more favorable to the defendant. [Citation.] As we explain below, we need not determine here whether counsel's actions were deficient, for [appellant] has failed to show prejudice." (People v. Seaton (2001) 26 Cal.4th 598, 666.) If counsel had moved to exclude appellant's statements on the ground that they were involuntary, it is not reasonably probable that the trial court would have granted the motion.