Descamps v. United States, 570 U.S. 254

ACCA increases sentences for defendants with three prior convictions for a violent felony, including burglary, arson, or extortion.
The Court uses the categorical approach to compare the statute's elements with the generic offense to determine ACCA predicates.
The modified categorical approach applies when the prior statute is divisible, allowing review of limited documents to identify which element formed the basis of the conviction.
Descamps was convicted under California § 459 (burglary) which covers entering locations with intent to commit theft or a felony, but does not require unlawful entry.
The Ninth Circuit held that the modified categorical approach could apply to § 459 to interpret the factual basis; this created a circuit split.
The Supreme Court held that the modified categorical approach cannot be used for an indivisible statute that broadens beyond the generic offense, so § 459 cannot serve as an ACCA predicate for Descamps.

Issue	Plaintiff's Argument	Defendant's Argument	Held
May the modified categorical approach apply to indivisible statutes?	Descamps argued it cannot apply to indivisible statutes like § 459.	The government argued the modified approach could identify the factual basis of the conviction.	No; modified categorical approach does not apply to indivisible statutes.
Does California § 459 burglary qualify as ACCA burglary predicate when it lacks the unlawful-entry element?	§ 459 is overbroad and cannot count as generic burglary.	A court could still determine the factual basis to see if it matches generic burglary.	§ 459 cannot serve as an ACCA predicate.
Does applying the modified approach raise Sixth Amendment concerns?	Allowing such factfinding would undermine Apprendi and jury findings.	The modified approach is a permissible tool to identify the conviction's basis.	The Court did not reach constitutional concerns because the approach is not applicable to indivisible statutes.

Taylor v. United States, 495 U.S. 575 (1990) (formal categorical approach; focus on elements)
Shepard v. United States, 544 U.S. 13 (2005) (plea-based inquiry for divisible statutes; limited documents allowed)
Nijhawan v. Holder, 557 U.S. 29 (2009) (modified categorical approach for several offenses; elements-focused rationale)
Johnson v. United States, 559 U.S. 133 (2010) (reaffirmed use of limited documents to identify the basis of conviction)
United States v. Aguila-Montes de Oca, 655 F.3d 915 (2011) (en banc; Ninth Circuit extended modified approach to indivisible statutes)