Yoo v. United States, 43 F.4th 64

Hyuk Kee Yoo ("Yoo"), a South Korean national residing in New York, faced seven South Korean embezzlement charges based on alleged conduct from 2008–2014; an Incheon court issued an arrest warrant in 2014.
South Korea requested extradition under the U.S.–Korea Extradition Treaty; U.S. prosecutors sought a warrant and certification under 18 U.S.C. § 3184 in 2020; Yoo was arrested and detained.
The Treaty’s Article 6 Lapse of Time provision states: “Extradition may be denied ... when the prosecution ... would have been barred because of the statute of limitations of the Requested State …”
A magistrate judge found probable cause and issued a Certificate of Extraditability, ruling that whether the statute of limitations bars extradition is a discretionary determination for the Secretary of State, not a mandatory judicial issue.
The district court denied Yoo’s habeas petition; Yoo appealed only the statute-of-limitations/timeliness question.
The Second Circuit affirmed, holding the Treaty’s use of “may” is permissive and that the determination whether to deny extradition on lapse-of-time grounds is for the relevant executive authority (here, the Secretary of State).

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether the word “may” in Article 6’s Lapse of Time provision is discretionary or mandatory	Yoo: “may” should be read as mandatory here; courts must decide timeliness and deny extradition if limitations have run	Government: “may” is permissive; Article 6 creates an executive discretion to deny extradition, not a court-imposed bar	Held: “may” is permissive; Article 6 is discretionary rather than mandatory
Who decides whether the statute of limitations bars extradition (court or executive)?	Yoo: Courts must make the timeliness determination and refuse extradition if time-barred	Government: That determination is a discretionary function of the Requested State’s executive (U.S. Secretary of State when U.S. is Requested State)	Held: That decision is for the Secretary of State (executive), not the extradition court; district court’s denial of habeas affirmed

Sacirbey v. Guccione, 589 F.3d 52 (2d Cir. 2009) (limits of habeas review in extradition proceedings)
Cheung v. United States, 213 F.3d 82 (2d Cir. 2000) (scope of judicial inquiry in extradition hearings)
Lo Duca v. United States, 93 F.3d 1100 (2d Cir. 1996) (judiciary interposes between executive and individual in extradition)
Skaftouros v. United States, 667 F.3d 144 (2d Cir. 2011) (court issues certificate; Secretary of State has final discretionary authority)
Patterson v. Wagner, 785 F.3d 1277 (9th Cir. 2015) (interpreting similar Article 6 language as permissive)
Martinez v. United States, 828 F.3d 451 (6th Cir. 2016) (survey of lapse-of-time treaty language; permissive vs mandatory provisions)
Jhirad v. Ferrandina, 536 F.2d 478 (2d Cir. 1976) (extradition orders treated as preliminary; habeas review appropriate)
Fernandez v. Phillips, 268 U.S. 311 (U.S. 1925) (habeas scope: jurisdiction, treaty coverage, and reasonable grounds)
United States v. Kin-Hong, 110 F.3d 103 (1st Cir. 1997) (Secretary may decline surrender on discretionary grounds)
Sumitomo Shoji Am., Inc. v. Avagliano, 457 U.S. 176 (U.S. 1982) (Executive interpretation of treaties entitled to great weight)