In United States v. Serrano, 16-432-cr; 17-461-cr (Kearse, Calabresi, Cabranes), the Second Circuit denied the defendant’s interlocutory appeal for lack of jurisdiction, holding that the collateral order doctrine is inapplicable to “non-colorable” double jeopardy claims and reaffirming its prior rulings that the denial of a Rule 29 motion does not fall within the scope of the doctrine. The Court infrequently polices the bounds of its appellate jurisdiction, and so it is useful to have this short decision on the subject of when a defendant may take an interlocutory appeal.
In June 2016, a jury convicted Pedro Serrano of possessing ammunition as a felon. Prior to sentencing and the entry of a final judgment, Serrano moved for a new trial pursuant to Rule 33 on the grounds that the District Court’s (Pauley, J.) jury instructions were flawed. Serrano also moved for a judgment of acquittal pursuant to Rule 29, arguing that there was insufficient evidence to sustain his conviction. In December 2016, the District Court denied Serrano’s Rule 29 motion, but granted his Rule 33 motion and ordered a new trial. Several days later, Serrano filed a letter motion with the District Court arguing that because there was insufficient evidence of his guilt and he had prevailed on his motion for a new trial, his retrial was barred by the Double Jeopardy Clause of the United States Constitution. In February 2017, the District Court denied Serrano’s double jeopardy motion on the grounds that no event had occurred to terminate his original jeopardy. The District Court further held that because Serrano’s double jeopardy claim was not colorable, it could not be appealed prior to the entry of a final judgment after his retrial. Serrano appealed the rulings on his Rule 29 and double jeopardy motions and moved to stay his retrial pending the outcome of his appeal. 
Judge Cabranes, writing for the Court, began with an overview of the collateral review doctrine. Pursuant to the doctrine, a criminal defendant may appeal a decision prior to conviction and the imposition of sentence where the order (1) conclusively determines the disputed question, (2) resolves an important issue completely separate from the merits of the action, and (3) is effectively unreviewable on appeal from a final judgment. Absent the satisfaction of these three factors, a circuit court lacks jurisdiction over the appeal of an interlocutory order.
The Court acknowledged that an order denying a pretrial motion to dismiss an indictment on double jeopardy grounds may be reviewable pursuant to the collateral order doctrine. It noted, however, that where the defendant’s double-jeopardy claim is frivolous and less-than-colorable, an interlocutory decision denying the claim may not be appealed prior to final judgment. Where there has been no event, such as an acquittal, to terminate original jeopardy, the defendant’s claim is not colorable and the collateral order doctrine is inapplicable.
Turning to the facts of the instant case, the Court concluded that Serrano did not have a colorable double jeopardy claim because he was still subject to original jeopardy. Serrano was not acquitted and his conviction had been set aside for reasons unrelated to the sufficiency of the evidence against him—to wit, a faulty jury instruction. As such, there had been no event that terminated original jeopardy in the case. Instead, the Court likened Serrano’s successful Rule 33 motion to the declaration of a mistrial, which typically does not terminate the original jeopardy in a case. Because Serrano lacked a colorable double jeopardy claim, the Court concluded that it did not have jurisdiction over his appeal.
In reaching this conclusion, the Court distinguished several of the cases on which Serrano relied, rejecting Serrano’s argument that it had jurisdiction over his interlocutory double jeopardy appeal simply because he challenged the sufficiency of the evidence against him. For example, the Court noted that in both United States v. Allen and Hoffler v. Bezio, which Serrano cited, the defendants raised their sufficiency-of-the-evidence claims on appeal from a final judgment. As such, these cases were inapposite with respect to the validity of his interlocutory appeal.
The Court also distinguished United States v. Wallach, a case in which the Second Circuit entertained an interlocutory double jeopardy appeal that included a sufficiency-of-the-evidence claim where the defendant had won his motion for a new trial on prosecutorial misconduct grounds. Although Wallach would appear to be on all fours with the instant case, the Court noted that unlike Serrano, Wallach had raised a colorable double jeopardy claim. While the Second Circuit ultimately rejected Wallach’s double jeopardy claim, it nonetheless held that his novel argument was colorable—and thus reviewable on interlocutory appeal—in light of existing Supreme Court double jeopardy precedent related to prosecutorial misconduct. Under certain circumstances, prosecutorial misconduct can lead to the government losing the opportunity to retry the defendant—in essense, the mistrial was caused by the government and not by circumstances beyond the parties’ control. Because Serrano’s double jeopardy claim was clearly meritless, however, the Court concluded that Wallach was readily distinguishable.
Finally, the Court turned to Serrano’s sufficiency-of-the-evidence appeal, which it readily denied for lack of jurisdiction in light of its prior ruling in United States v. Ferguson that “the denial of a Rule 29 motion does not fall within the narrow scope of the collateral order doctrine.” 
Although the holding in this case forecloses a potential avenue of interlocutory review for defendants facing retrial, it serves as a good reminder of the proposition set forth in Wallach—the Second Circuit will entertain interlocutory appeals under the collateral review doctrine of certain double jeopardy arguments provided that the defendant’s claims are at least colorable under existing Supreme Court precedent.