Descamps v. United States, 570 U.S. ___, 133 S. Ct. 2276 (2013)
In an 8-1 decision  written by Justice Kagan, the Supreme Court held that sentencing courts must apply the categorical approach – and only the categorical approach – to a federal defendant unless the underlying statute of conviction is ‘divisible.’
Descamps concerns the analytical approach courts must undertake when determining what federal consequences (usually sentence enhancement or removal) attach to a particular conviction. The default approach is called the categorical approach, wherein the court compares the elements set forth in the criminal statute to the INA removal ground or other federal law at issue. The facts in the criminal case are irrelevant. All that matters are the elements of the statute of conviction. The rationale for an elements-centric approach, as the Court explained in Descamps, is multifold: it comports with the text and history of the statutes it was created to apply (often the Armed Career Criminal Act and the INA), it avoids Sixth Amendment concerns that would arise form sentencing courts’ making factual findings that belong to juries, and it averts the practical difficulties and potential unfairness of a factual approach.
What Descamps makes clear is that deviation from the categorical approach (i.e., application of a modified categorical approach) is permitted in only one scenario: where the relevant criminal statute expressly defines more than one offense. In cases involving these statutes -- called ‘divisible’ statutes because they set out one or more of the elements of the offense in the alternative, e.g., burglary involving entry into a building or an automobile – courts may consult a limited universe of extra-statutory documents for the purpose of ascertaining which elements of the statute the defendant was convicted of. The Court also clarified that in a case involving an overbroad statute (i.e., one that criminalizes a broad range of conduct), it is impermissible to apply a modified categoriacal approach.
Although Descamps arose in the sentencing context, the Court’s analysis should be applied similarly in the immigration context.
Descamps abrogated the Ninth Circuit’s en banc decision in United States v. Aguila-Montes de Oca, 655 F. 3d 915 (9th Cir. 2011).
The National Immigration Project of the National Lawyers Guild and the Immigrant Defense Project issued a Practice Advisory  summarizing the holding of Descamps, explaining its applicability to immigration cases, and exploring the case’s implications.
Justices Kennedy and Thomas filed concurring opinions. Justice Alito dissented.