United States v. Solano, 966 F.3d 184

Solano, a long‑time commercial truck driver, was tried for conspiracy and attempted possession with intent to distribute cocaine after CBP found ~13.6 kg of cocaine in a sealed shipping container (June 1) and HSI conducted a controlled delivery on June 7.
On June 7 Solano picked up the resealed container at Red Hook, delivered it to a Bronx warehouse, and was arrested; the central disputed issue at trial was whether Solano knew the container contained drugs before he picked it up.
Three HSI officers testified that Solano, during a second post‑arrest interview, admitted prior knowledge that the container contained drugs; Solano testified he never made such admissions and had called an HSI agent for reassurance before leaving the terminal.
The officers did not audio‑record the interrogation, Barrois took no notes of the alleged confession, Corvi’s notes contained no admission, and no written confession or signed Miranda waiver was produced.
The district court instructed jurors that "any" witness who has an interest in the outcome of the case has "a motive . . . to testify falsely"; Solano did not object at trial. The jury convicted on attempt (acquitted on conspiracy).
The Second Circuit held the jury instruction was plain error, prejudicial given the credibility contest at trial, vacated the conviction, and remanded for further proceedings.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether the jury instruction that "any" interested witness "has a motive to testify falsely" is permissible	Instruction was a permissible credibility instruction applicable to all witnesses and harmless	The instruction explicitly and impermissibly imputes a motive to lie to a testifying defendant, undermining presumption of innocence	Instruction was error (violates Gaines/Brutus line)
Whether the error is "plain" under Rule 52(b)	Any error was not plain at trial and is subject to forfeiture	Error is squarely prohibited by precedent and thus plain on appeal	Error was plain at time of appellate review
Whether the error affected substantial rights (prejudice)	Government argued evidence supported conviction and any error was harmless	Credibility was central; officer testimony of admissions was undocumented and conflicted with defendant and other witnesses, creating reasonable probability of prejudice	Error prejudicial; reasonable probability it affected outcome
Appropriate remedy	Affirm or hold harmless	Vacate conviction and remand	Conviction vacated and case remanded for further proceedings

United States v. Gaines, 457 F.3d 238 (2d Cir. 2006) (prohibits instructions that a testifying defendant's interest creates a motive to lie)
United States v. Brutus, 505 F.3d 80 (2d Cir. 2007) (reinforces Gaines; such instructions undermine presumption of innocence)
United States v. Mazza, [citation="594 F. App'x 705"] (2d Cir. 2014) (applies Gaines/Brutus; vacated convictions where credibility was dispositive)
United States v. Mehta, 919 F.3d 175 (2d Cir. 2019) (reiterates that telling jurors defendant's interest "creates a motive for false testimony" is forbidden)
United States v. Munoz, [citation="765 F. App'x 547"] (2d Cir. 2019) (holds instruction erroneous though harmless given overwhelming evidence)
United States v. Olano, 507 U.S. 725 (1993) (sets four‑part plain‑error test)
Dominguez Benitez v. United States, 542 U.S. 74 (2004) (explains "reasonable probability" prejudice standard under Rule 52(b))
Henderson v. United States, 568 U.S. 266 (2013) (error may be plain at time of appellate review)