We acknowledge that this court has previously determined that forfeiture proceedings are "quasi-criminal" and potentially punitive in effect, even though civil in nature. See State v. Nineteen Thousand Two Hundred and Thirty-Eight Dollars ($19,238.00) in United States Currency, 157 Ariz. 178, 182, 755 P.2d 1166, 1170 (App. 1987); One 1974 Mercedes-Benz v. State, 121 Ariz. 549, 551, 592 P.2d 383, 385 (App. 1979). However, that observation was made in the context of the "multiple punishment" area of double jeopardy inquiry rather than in a multiple prosecution context.

Id. at 441. Numerous courts give criminal suppression hearing decisions, adverse to the defendant, collateral estoppel effect in subsequent civil litigation where a conviction followed the suppression hearing. Searing v. Hayes, 684 F.2d 694, 696-97 (10th Cir. 1982); Lucien v. Roegner, 574 F. Supp. 118, 120-21 (N.D.Ill. 1983); Weinstein v. Mueller, 563 F. Supp. 923, 929 (N.D.Cal. 1982); Lomax v. Smith, 501 F. Supp. 119, 121-23 (E.D.Pa. 1980); Nash v. Reedel, 86 F.R.D. 13, 15 (E.D.Pa. 1980); Manis v. United States, 467 F. Supp. 828, 830 (E.D.Tenn. 1979); Rodriguez v. Beame, 423 F. Supp. 906, 908 (S.D.N Y 1976) (where the defendant testified at the pretrial hearing); Matter of One 1974 Mercedes Benz, 592 P.2d 383, 386 (Ariz.App. 1979). However, none of these cases discuss the problem of conflicting motivation or consider whether collateral estoppel should apply when the defendant does not testify at the suppression hearing.

But cf. United States v. Ursery, 518 U.S. 267, 292, 116 S.Ct. 2135, 2149, 135 L.Ed.2d 549, 571 (1996) (holding that federal " in rem civil forfeitures are neither `punishment' nor criminal for purposes of the Double Jeopardy Clause"). Arizona courts have impliedly recognized that Fourth Amendment principles may apply to forfeiture actions. See Wohlstrom v. Buchanan, 180 Ariz. 389, 392, 884 P.2d 687, 690 (1994) (noting that forfeiture claimants "ought to have an opportunity to present" a "colorable [Fourth Amendment] argument," but not deciding "whether the exclusionary rule applies in this or other forfeiture proceedings"); In re $315,900.00; In re One 1974 Mercedes Benz, 121 Ariz. 549, 592 P.2d 383 (App. 1979) (recognizing United States Supreme Court application of Fourth and Fifth Amendments to in rem forfeiture). It is undisputed that the Sociology Department employee's opening of the package and discovery of cash therein did not offend the Fourth Amendment.

In our opinion, this issue is not dispositive of the action taken by the trial court. We recently held in In re One 1974 Mercedes Benz, Ariz., 592 P.2d 383 (1979) that the forfeiting of a vehicle arising out of criminal activity is merely additional punishment extracted against the owner for the underlying crime. Given this posture of the forfeiture proceeding, this court was of the opinion that, at least in this quasi criminal setting, it owed a duty to bring to the attention of counsel the issue it felt was dispositive of the appeal. This was done and both counsel have filed supplemental briefs touching on the issue raised by the court.