United States v. Marcus Walker, 990 F.3d 316

Walker acted as a lookout and organizer in a home robbery during which an accomplice held a 12‑year‑old at gunpoint; codefendants pleaded guilty and Walker was tried.
Charges: conspiracy to commit Hobbs Act robbery (18 U.S.C. §1951), attempted Hobbs Act robbery (18 U.S.C. §1951), and using/carrying a firearm in relation to a crime of violence (18 U.S.C. §924(c)).
Government relied on testimony from three cooperating witnesses and Agent Henning’s phone‑records and cell‑site location information (CSLI); CSLI was obtained under a Stored Communications Act order.
Trial court admitted CSLI without a warrant; Henning testified about the records and his interviews with cooperators; defense objected on Fourth and Sixth Amendment grounds and to vouching.
Jury convicted on all counts; district sentence was 72 months on the substantive counts plus a consecutive 60 months on the §924(c) count; Walker appealed raising four main errors.
On rehearing after United States v. Davis, the Third Circuit affirmed: CSLI admissible under good‑faith rule; Henning’s testimony did not plainly violate the Confrontation Clause or amount to improper vouching; attempted Hobbs Act robbery is categorically a crime of violence under §924(c)(3)(A); jury instructions were adequate.

Issue	Walker's Argument	Government's Argument	Held
Admissibility of CSLI (Carpenter)	CSLI required a warrant; admitting SCA‑obtained CSLI was error	Agents relied in good faith on then‑valid court order/statutory procedure and binding precedent	Admitted: no plain error under good‑faith exception per Goldstein
Henning’s testimony / Confrontation Clause & vouching	Henning testified to analyses/reports he did not prepare (testimonial) and vouched for cooperators	Henning reviewed/participated in the analysis and testimony did not improperly bolster witnesses	No plain Confrontation or vouching error; testimony permissible and not outcome‑determinative
Whether attempted Hobbs Act robbery is a §924(c) "crime of violence"	Attempt need not involve an attempted use/threat of physical force; attempt may be mere intent plus nonviolent step	§924(c)(3)(A) expressly includes "attempted use"; attempt offenses necessarily include attempt to each element, so attempted violent crimes are crimes of violence	Attempted Hobbs Act robbery is categorically a crime of violence under the elements clause; §924(c) conviction stands
Jury instructions (predicate ambiguity)	Instructions allowed conviction if defendant or accomplice used firearm, leaving ambiguity whether conspiracy or attempt was predicate	Instructions repeatedly identified attempted Hobbs Act robbery as predicate; jury was adequately instructed	No reversible error; instructions made attempt the predicate sufficiently clear

United States v. Davis, 139 S. Ct. 2319 (2019) (held §924(c) residual clause unconstitutionally vague)
Carpenter v. United States, 138 S. Ct. 2206 (2018) (warrant required for historical CSLI absent exception)
United States v. Goldstein, 914 F.3d 200 (3d Cir. 2019) (good‑faith exception permitted admission of CSLI obtained under then‑valid order)
United States v. Robinson, 844 F.3d 137 (3d Cir. 2016) (prior Third Circuit consideration of Hobbs Act robbery as crime of violence)
United States v. Hill, 877 F.3d 717 (7th Cir. 2017) (attempt to a violent crime counts as attempt to each element for ACCA)
United States v. St. Hubert, 909 F.3d 335 (11th Cir. 2018) (attempted Hobbs Act robbery is a crime of violence)
United States v. Dominguez, 954 F.3d 1251 (9th Cir. 2020) (same conclusion on attempted Hobbs Act robbery)
United States v. Taylor, 979 F.3d 203 (4th Cir. 2020) (held attempted Hobbs Act robbery is not categorically a crime of violence)
Moncrieffe v. Holder, 569 U.S. 184 (2013) (explaining the categorical approach)
United States v. Resendiz‑Ponce, 549 U.S. 102 (2007) (discussing attempt and the substantial‑step requirement)