United States v. Rivera-Berrios, 968 F.3d 130

Rivera-Berríos was observed tossing a Glock machine pistol (with an automatic-fire device) and an 18‑round high‑capacity magazine out a restaurant window during surveillance; he was arrested and indicted.
Initial indictment charged felon‑in‑possession and illegal possession of a machine gun; the felon‑in‑possession count was later dropped when the government learned he had no prior convictions.
Rivera‑Berríos pleaded guilty to possession of a machine gun; the PSI calculated a Guidelines range of 24–30 months after a 3‑level acceptance reduction and Criminal History Category I.
Both parties recommended a low‑end Guidelines sentence, but the district court imposed a 42‑month upward variance (one year above the top of the range), citing the dangerousness and pervasiveness of machine guns and violent crime in Puerto Rico.
On appeal Rivera‑Berríos challenged the upward variance as procedurally improper because the court relied on a factor (the firearm being a machine gun) already fully accounted for in the Guidelines and failed to identify case‑specific aggravating circumstances.

Issue	Government Argument	Rivera‑Berríos Argument	Held
Whether the district court permissibly imposed a one‑year upward variance	The court properly considered the seriousness of the offense, community violence, the nature of machine guns, ammunition and the defendant’s company; appellate review should be deferential	The upward variance relied solely on the fact a machine gun was involved—a factor already fully accounted for by the Guidelines—and the court failed to identify any case‑specific aggravating circumstances	Vacated and remanded: the court abused its discretion by relying on a factor already accounted for in the Guidelines without explaining why it deserved extra weight; remand for within‑Guidelines resentencing

Gall v. United States, 552 U.S. 38 (review standard for sentencing reasonableness)
United States v. Booker, 543 U.S. 220 (explaining advisory nature of Guidelines)
Spears v. United States, 555 U.S. 261 (Guidelines intended to cover the mine‑run of cases)
United States v. Díaz‑Lugo, 963 F.3d 145 (sentencing court must give extra weight explanation when relying on a factor already in the Guidelines)
United States v. Fields, 858 F.3d 24 (requirements for explaining upward variance)
United States v. Montero‑Montero, 817 F.3d 35 (burden of explanation increases for outside‑range sentences)
United States v. Flores‑Machicote, 706 F.3d 16 (section 3553(a) factors must be tied to case‑specific facts)
United States v. Ofray‑Campos, 534 F.3d 1 (generic references to community violence do not justify upward variance)