United States v. Duong, 2017 U.S. App. LEXIS 2552

In 2015 three defendants (Duong, Baker, Anthony) were indicted for child sex trafficking and conspiracy under 18 U.S.C. § 1591 and § 1594; the sole disputed element on appeal is mens rea as to the victim’s age.
The superseding indictment alleged only that defendants "had a reasonable opportunity to observe" the victims (two minors), omitting explicit allegations of knowledge or reckless disregard of age.
The government sought to prove mens rea at trial solely via the "reasonable opportunity to observe" language and moved to preclude mistake-of-age defenses; the district court denied that motion and required evidence of knowledge or reckless disregard, then dismissed the superseding indictment as legally deficient.
The government appealed, arguing § 1591(c) allows conviction when the prosecution proves the defendant had a reasonable opportunity to observe the victim, without separately proving actual knowledge or reckless disregard.
The Tenth Circuit reviewed the statutory text and context de novo and concluded § 1591(c) provides a third, independent method to satisfy the age-related mens rea: knowledge, reckless disregard, or reasonable opportunity to observe.
The court reversed the dismissal as to both the substantive and conspiracy counts, holding the superseding indictment was sufficient when it alleged reasonable opportunity to observe.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether 18 U.S.C. § 1591(c) permits proving mens rea as to victim's age solely by showing defendant had a reasonable opportunity to observe the victim	Gov: § 1591(c) "need not prove" language plainly relieves the government of proving knowledge when defendant had reasonable opportunity to observe; thus it is an independent method to satisfy mens rea	Defs: § 1591(c) should be read to permit only proof of reckless disregard (not eliminate need for knowledge or reckless disregard); reading it otherwise renders reckless-disregard amendment superfluous	Held: § 1591(c) is unambiguous and provides an additional, independent method to satisfy age mens rea—knowledge, reckless disregard, or reasonable opportunity to observe (reversed dismissal)
Whether the indictment’s allegation of "reasonable opportunity to observe" adequately pleads mens rea for the conspiracy count	Gov: pleading reasonable opportunity to observe sufficiently alleges the mens rea element of conspiracy under § 1591	Defs: conspiracy requires the conspirators to have known the victim was a minor when they agreed; reasonable-opportunity pleading cannot substitute for actual knowledge at formation	Held: Allegation that defendants had a reasonable opportunity to observe the victim charges the mens rea for the conspiracy counts under the court’s reading of § 1591(c)

United States v. Copeland, 820 F.3d 809 (5th Cir.) (endorsing § 1591(c) as an independent basis for proving mens rea)
United States v. Robinson, 702 F.3d 22 (2d Cir.) (interpreting § 1591(c) to allow conviction based on reasonable opportunity to observe)
United States v. Mozie, 752 F.3d 1271 (11th Cir.) (discussing due process and mens rea under § 1591; stated that reasonable opportunity negates need to prove actual knowledge)
United States v. Salgado, 519 F.3d 411 (7th Cir.) (holding conspiracy is complete before the substantive crime and discussing mens rea at agreement formation)
United States v. Brinson, 772 F.3d 1314 (10th Cir.) (setting out § 1591 elements and addressing sufficiency of age-mens rea evidence)
United States v. Todd, 446 F.3d 1062 (10th Cir.) (standard of review for dismissal of an indictment)