During a custodial interrogation, may police ignore an individual's repeated and unambiguous demands to 'cut off questioning'?

QUESTIONS PRESENTED In Miranda v. Arizona, the Court announced prophylactic rules deemed necessary to safeguard the Fifth Amendment privilege against self-incrimination, including an individual's "right to cut off questioning" during custodial interrogation. 384 U.S. 436, 474 (1966); Michigan v. Mosley, 423 U.S. 96, 103-04 (1975). Since then, the Court has reiterated that whether a suspect unambiguously invoked his Miranda rights requires an "objective inquiry." Berghuis v. Thompkins, 560 U.S. 370, 381 (2010); Davis v. United States, 512 U.S. 452, 459 (1994); see also Connecticut v. Barrett, 479 U.S. 523, 529 (1987) ("Interpretation is only required where the defendant's words, understood as ordinary people would understand them, are ambiguous."). And yet, lower courts remain deeply divided on how and when an individual invokes "the right to cut off questioning," and whether speculation into an individual's subjective motivations may render a plain Miranda invocation ambiguous. The questions presented are: 1. During a custodial interrogation, may police ignore an individual's repeated and unambiguous demands to "cut off questioning"? 2. May speculation into an individual's subjective motivations provide the context that renders an otherwise plain Miranda invocation ambiguous?