1. In Marinello v. United States, 138 S. Ct. 1101, 1109-10 (2018), the Court held that, to prove obstruction, the government must show that the defendant's efforts had a nexus to a particular proceeding and that the proceeding itself was pending or "reasonably foreseeable by the defendant." After Marinello, does the nexus element require a mens rea of:

(a) knowledge that the defendant's conduct will affect an existing investigatory proceeding, as the Sixth Circuit has held;

(b) knowledge that the conduct will affect a foreseeable proceeding, as the Fourth and Eighth Circuits have held; or

(c) no knowledge as to how the conduct will affect a foreseeable proceeding, as the Ninth Circuit held in this case?

2. The Court and a vast majority of circuits agree that a waiver of one's Miranda rights must be knowing and intelligent, taking into account the totality of the circumstances. Does the Ninth Circuit's factor-based tests for determining a waiver's validity improperly narrow this totality-of-the-circumstances test?

Whether the nexus element for obstruction requires knowledge that the defendant's conduct will affect an existing or foreseeable proceeding