A collateral order is not final in the traditional sense,
but conclusively resolves an important issue separate from the merits, and is
effectively unreviewable on appeal.
Collateral order appeals are permitted only in exceptional
circumstances, including when double jeopardy may be at issue. The Court adopted a test used by most of the
other circuits to determine whether double jeopardy is sufficiently implicated
to permit collateral order review: would
the claim, if successful, require dismissal of – at a minimum – an entire
count?
Here, the defendants were acquitted of several substantive
counts predicated on a mailing or email relating to a particular
transaction. They argued that the jury
necessarily decided that they lacked criminal intent as to those transactions. Thus, they argued, the government should be
precluded from presenting any evidence of those transactions at trial. They conceded, however, that this would not
prevent the government from presenting other evidence of criminal intent on the
remaining counts, and that even if they prevailed in precluding the specified
evidence, no count of the indictment would be dismissed. Thus, the Court concluded, it lacked
jurisdiction. (In the process, it
rejected an argument that United States
v. Serafini, 167 F.3d 812 (3d Cir. 1999), which permits the government to
seek review of orders of dismissal excising portions of counts, authorized
review here, distinguishing the statutory provision – 18 U.S.C. § 3731 -- at
issue.)
The Court held that the constructive amendment aspect of the
motion was not appealable either, because constructive amendment, if it occurs,
may be addressed on appeal after trial.
Finally, the Court refused to grant mandamus relief, because
it identified no irreparable harm.