United States v. Santiago, 947 F.3d 1

Santiago pled guilty in June 2017 to being a felon in possession of a firearm and ammunition (18 U.S.C. § 922(g)(1)).
He had a prior state felony conviction (conspiracy to distribute) and had been sentenced in absentia to seven years in state court before the federal offense but had not yet begun serving that term when the federal offense occurred.
On April 3, 2017, police observed Santiago discard a firearm while fleeing; he admitted ownership and lack of a permit.
The district court calculated a total offense level of 19 and criminal history category III, producing a Guidelines range of 37–46 months, and imposed a 37-month federal sentence to run consecutively to the state term.
Santiago appealed, arguing the district court treated Sentencing Guideline §5G1.3(a) as mandatory in violation of United States v. Booker; the government invoked an appeal waiver in Santiago’s plea agreement (covering sentences within or below the Guidelines range as determined by the court).
The First Circuit held the appeal waiver enforceable, found no miscarriage-of-justice exception, and affirmed the consecutive sentence.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether the district court violated Booker by treating U.S.S.G. §5G1.3(a) as mandatory	Government: guideline recommends consecutive sentence and court could lawfully impose consecutive sentence	Santiago: court treated §5G1.3(a) as mandatory, violating Booker; would have imposed concurrent sentence otherwise	Waived — appeal barred; court did not find miscarriage of justice and left the within-Guidelines consecutive sentence in place
Whether Santiago's appeal waiver is enforceable or excused by miscarriage-of-justice	Government: waiver was knowing and voluntary and the sentence was within the agreed Guidelines range, so waiver bars the appeal	Santiago: combined federal and state time is excessive; his circumstances warrant excusing the waiver	Waiver enforceable; miscarriage-of-justice exception not satisfied; appeal dismissed and judgment affirmed

United States v. Booker, 543 U.S. 220 (2005) (held Guidelines are advisory post-Booker)
United States v. Teeter, 257 F.3d 14 (1st Cir. 2001) (standards for enforcing appeal waivers and miscarriage-of-justice exception)
United States v. Davis, 923 F.3d 228 (1st Cir. 2019) (discussing application of appeal-waiver standards)
United States v. Cardona-Díaz, 524 F.3d 20 (1st Cir. 2008) (claims of mandatory-Guidelines application are typically too trivial to overcome waivers)
United States v. Cabrera-Rivera, 893 F.3d 14 (1st Cir. 2018) (upholding within-Guidelines sentences against miscarriage-of-justice challenges)
United States v. Gil-Quezada, 445 F.3d 33 (1st Cir. 2006) (describing the high threshold for miscarriage-of-justice relief)