*841 OPINION
The United States appeals from an interlocutory order in its prosecution against Edward Dominguez. The district court suppressed key evidence on the basis of issue preclusion because the same evidence had been suppressed in a previous Michigan state court proceeding against Dominguez. Because the district court misinterpreted applicable Michigan law, we REVERSE this order and remand for further proceedings consistent with our holdings.
I
This case presents the interesting issue of what preclusive force a Michigan state criminal proceeding may have upon the course of a subsequent federal criminal proceeding. The United States charges Dominguez with drug trafficking, under 21 U.S.C. §§ 841(a)(1) and (b)(l)(B)(ii). Its case depends largely upon evidence seized in Dominguez’s automobile pursuant to a Michigan state search warrant. That warrant, in turn, was issued based upon an affidavit setting forth the report of a confidential informant that he had seen a kilogram of cocaine stored in a secret compartment of an automobile registered to Ruben Rodriguez, an alias for Dominguez.
A joint state-federal task force, the Western Wayne Interdiction Team, executed the search warrant and found cocaine in the car (although not in a secret compartment). The State of Michigan then brought state-law drug-trafficking charges against Dominguez. The state trial court suppressed all evidence obtained as a result of the search warrant, holding that the warrant had been obtained in violation of the Fourth Amendment to the United States Constitution. The court then dismissed the state charges against Dominguez without prejudice. Michigan did not appeal from that evidentiary ruling.
After the state case was dismissed, the United States brought this action based on federal-law charges similar to those brought by Michigan in the prior state court action. Dominguez again moved to suppress the evidence. The district court granted his motion because it found that the United States' was collaterally es-topped from litigating that issue as a privy to the state of Michigan. The United States appeals.
II
We review
de novo
a district court decision based on claim or issue preclusion.
Heyliger v. State Univ. & Cmty. Coll. Sys. of Tenn.,
Of course, a Michigan state court never could sit in judgment over the prosecution- of a federal crime, as 18 U.S.C.
*842
§ 3231 creates exclusive federal criminal jurisdiction, so there is no Michigan case law directly on point. This by itself does not prevent us from applying the Full Faith and Credit Act. The Supreme Court resolved a similar issue in
Marrese v. American Acad. of Orthopaedic Surgeons,
Therefore, even though the Michigan courts could never literally confront our situation, we can and must resolve the Michigan law questions before asking whether some exception to the Full Faith and Credit Act may apply.
Ill
Under Michigan law, the party asserting preclusion bears the burden of proof.
Detroit v. Qualls,
The district court, and Dominguez, rely entirely upon
In re Forfeiture of $1,159,420,
*843
To begin with,
In re Forfeiture
is an appellate-level decision, so it can give us only limited guidance in emulating the Michigan Supreme Court.
See King v. Order of United Commercial Travelers of America,
Privity between separate sovereigns is usually found only after much factual analysis.
See United States v. ITT Rayonier,
Nor are the facts of
In re Forfeiture
so like those before us as to demand the same outcome. Unlike the second prosecutor in that case, the United States is not an arguable stranger to the dispute now seeking to assert issue preclusion; rather, we are asked to apply issue preclusion
against
the newcomer based upon a finding of privity. The latter is a weightier determination. Many jurisdictions have dispensed with the privity requirement altogether as to the party asserting preclusion,
Blonder-Tongue Labs., Inc. v. Univ. of Ill. Found.,
Michigan maintains the traditional rule of “mutuality of estoppel,” requiring both the party to be precluded and the party asserting preclusion to have been represented at the prior proceeding.
Lichon v. American Universal Ins. Co.,
The Michigan Supreme Court has recently provided more relevant, guidance.
Baraga County v. State Tax Comm’n,
The
Baraga County
dictum commands our respect, the more so because it accords with the general understanding of the relationship between federal and state prosecutors. This court has opined, albeit only in dictum and without analysis of state law, that a Michigan and a United States prosecutor were not the same party.
United States v. Lloyd,
In his appellate brief, and at oral argument, Dominguez asserted that the United States did direct the state prosecution. But there is no evidence in the record to support this argument. Dominguez merely asserts that a state-employed Assistant Attorney General on the state prosecution team was also designated as an Assistant United States Attorney involved in the federal prosecution. This court will not affirm based upon a mere assertion made for the first time at the appellate level. This is particularly so, because even if supported, the facts asserted would not prove control or agency: Dominguez does not assert that this particular state prose *845 cutor could or did effectively recommend dismissal, nor that he was subject to federal control during the state proceedings.
We conclude that a Michigan court applying Michigan law would not find based upon the facts in the record that the United States was in privity with the Michigan prosecutor in the prior state proceeding. Therefore, collateral estoppel does not bar the introduction of this evidence.
Even if Michigan law did create privity between the federal and state governments as a matter of law, we would have grave doubts as to the propriety of estop-ping a federal prosecutor on these grounds. As seen in this case, issue preclusion often concludes an action as surely as claim preclusion.
See Ashe v. Swenson,
The problem is illustrated by comparison to Mich. Comp. Laws Ann. § 333.7409, which bars a Michigan prosecution for drug trafficking based upon acts that have already given rise to a criminal prosecution in another jurisdiction. Dominguez ui’ges that a Michigan court would analogize from this statute and bar a successive federal prosecution as well. But this would let a hypothetical Michigan court do what the state legislature may not. Michigan clearly could not by statute restrain federal prosecutors from enforcing federal criminal laws as to Michigan convicts. How, then, can its courts create a uniquely-targeted rule of preclusion to do precisely that?
The United States in its role as prosecutor is very different from the usual civil litigator. In
Standefer v. United States,
Such an expansive reading of the Act could have mischievous results. The federal government would doubtless be obliged to involve itself closely in all Michigan criminal prosecutions implicating some federal crime. The resulting interference with the Michigan Attorney General’s office would waste federal and state resources. It might also impair the very
*846
goal of the Full Faith and Credit Act, comity.
See Migra,
Because the United States was not party or privy to the state court proceeding against Dominguez, it is not collaterally estopped from litigating the admissibility of the evidence against Dominguez, and we therefore REVERSE the order of the district court and remand for further proceedings in accord with this opinion.
Notes
. The
In re Forfeiture
court also found privily on the other side of the equation, reasoning that Hawkins’s interests as criminal defendant represented his and his family's interests as property owners.
. The United States urges us to adopt Charles as a rule of federal common law. But it is not clear whether Charles and related cases establish a rule of federal law or simply recognize a commonality in state law throughout the First Circuit.
