Appeal from two judgments of the Supreme Court (Ellison, J.), rendered July 27, 1987 in Tompkins County, convicting defendants upon their pleas of guilty of the crime of conspiracy in the fourth degree.
In late 1986 defendants were each indicted in Tompkins County on one count of conspiracy in the fourth degree, charging that they had agreed, along with five other defendants, to engage in an illegal narcotics operation with Eric Degen, an unindicted coconspirator, concerning the possession and sale of cocaine. The indictment was based on evidence obtained through the use of an eavesdropping warrant and Degen’s testimony before the Grand Jury. The warrant was based in part on information received by a confidential informant. In December 1986 defendants both moved for, inter alia, dismissal of the indictment and suppression of the evidence gathered pursuant to the eavesdropping warrant. By orders dated April 21, 1987 Supreme Court denied the motions, finding the eavesdropping warrant to have been properly issued. However, prior to Supreme Court’s decision, County Court of Chenango County, on April 14, 1987, in a separate case, found that the same eavesdropping warrant involved herein was invalid because the reliability of the informant had not been sufficiently established. As a result, defendants moved on April 29, 1987 for reargument of their prior motions, claiming that Supreme Court was bound under the doctrine of collateral estoppel by County Court’s prior determination on the question of the warrant’s validity. Supreme Court rejected this claim and denied the motions to reargue. Defendants each then pleaded guilty to the charged crime, were sentenced and now appeal.
*896We affirm. In so doing, we turn initially to defendants’ claim that collateral estoppel is applicable to the facts of this case. By way of background, we note that this doctrine is not as relevant in criminal cases as it is in civil actions and is applied with greater flexibility in criminal matters (see, People v Sailor, 65 NY2d 224, 228, cert denied 474 US 982). In civil actions the primary concern is with the swift resolution of private disputes, while in criminal litigation the main focus is to reach a correct result (People v Plevy, 52 NY2d 58, 64). As the Court of Appeals has emphasized, "Strong policy considerations militate against giving issues determined in prior litigation preclusive effect in a criminal case” (People v Fagan, 66 NY2d 815, 816).
Bearing these principles in mind, and with respect to the case at hand, it has been determined that collateral estoppel applies in criminal matters only when there has been a valid and final judgment in the prior proceeding (People v Goodman, 69 NY2d 32, 37-38). Under the facts of this case, this requirement has not been satisfied. In the Chenango County proceeding, the eavesdropping warrant was found to be invalid and the indictment was dismissed. This was not a final decision to which the doctrine of collateral estoppel could apply. The Court of Appeals dealt with a similar situation in Matter of McGrath v. Gold (36 NY2d 406). There, a search warrant was deemed invalid resulting in a dismissal of the indictment in the prior proceeding. In deciding that the doctrine of collateral estoppel did not apply in the second proceeding, the court noted that: "there was not the requisite finality since the dismissal [in the first proceeding] would not bar a trial based on a subsequent accusatory instrument charging the identical offenses * * * and since the dismissal was based on the suppression order which was interlocutory in nature” (supra, at 412 [citations omitted]). (See also, People v Sanders, 71 NY2d 946.) Therefore, based on the analysis set forth in McGrath, the doctrine of collateral estoppel does not apply in the instant case. Cases which have applied the doctrine are factually dissimilar and have involved final judgments (see, e.g., People v Plevy, 67 AD2d 591, 597, affd 52 NY2d 58 [order denying suppression in first proceeding became final and reviewable on appeal from the defendant’s conviction and therefore formed the basis for estoppel]; People v Nieves, 106 Misc 2d 395 [evidence suppressed in first proceeding and the People affirmatively moved to dismiss the charges for lack of evidence therefore the order became final and subject to estoppel]).
*897We also reject defendants’ contention that sufficient probable cause did not exist to support the issuance of the eavesdropping warrant. Here, it is not disputed that the informant used in acquiring the warrant had an adequate basis of knowledge from which he gave his information to the police; rather, the question is whether he was sufficiently reliable (see, Aguilar v Texas, 378 US 108; People v Johnson, 66 NY2d 398, 400; People v Griminger, 127 AD2d 74, 82-83, affd 71 NY2d 635). In our view, reliability was adequately established by police observations corroborative of the information received and the facts observed were sufficiently suggestive of criminal activity (see, People v Elwell, 50 NY2d 231, 237). A pen register* had been placed on a telephone line of a suspected drug dealer which showed that calls had been made to individuals with prior drug charges and convictions. Several of these individuals corresponded to the information supplied by the informant. Furthermore, the officer in contact with the informant personally overheard a conversation between the informant and Degen during which Degen explained his immediate plans with regard to selling cocaine. Given these facts, Supreme Court properly determined that probable cause existed for the granting of the eavesdropping warrant.
As a final matter, by pleading guilty, defendants waived any claims relating to the sufficiency of the evidence before the Grand Jury (see, People v Dunbar, 53 NY2d 868, 871).
Judgments affirmed. Mahoney, P. J., Kane and Yesawich, Jr., JJ., concur.
A pen register is a device used to monitor telephone numbers called from a monitored telephone.