United States Court of Appeals
                            FOR THE EIGHTH CIRCUIT
                                    ___________

                                    No. 08-3916
                                    ___________

United States of America,                *
                                         *
             Appellee,                   *
                                         * Appeal from the United States
      v.                                 * District Court for the
                                         * Eastern District of Missouri.
Avery West, also known as Pig,           *
                                         *
             Appellant.                  *
                                    ___________

                              Submitted: September 25, 2009
                                 Filed: December 21, 2009
                                  ___________

Before BYE, ARNOLD, and SMITH, Circuit Judges.
                            ___________

ARNOLD, Circuit Judge.

      A jury convicted Avery West of conspiring to possess cocaine and cocaine base
with the intent to distribute it, see 21 U.S.C. §§ 841(a)(1), 846, 851(a), possessing
cocaine and cocaine base (in two separate counts) with the intent to distribute it, see
21 U.S.C. § 841(a), and conspiring to launder money, see 18 U.S.C.
§ 1956(a)(1)(A)(i), (B)(i). After the district court1 imposed a 400-month sentence,
Mr. West appealed, challenging the denial of his motions to suppress evidence. We
affirm.

      1
        The Honorable Donald J. Stohr, United States District Judge for the Eastern
District of Missouri.
       Before trial, Mr. West filed separate motions to suppress drugs seized during
a search of his home and to suppress the content of wiretapped phone conversations.
After conducting evidentiary hearings, a magistrate judge2 filed a report and
recommendation as to each motion; she made factual findings, recommended that the
motions be denied, and notified the parties that a failure to object might result in a
"waiver of the right to appeal questions of fact." Mr. West filed no objections, and the
district court adopted the magistrate's reports and recommendations in full. See
28 U.S.C. § 636(b)(1). At trial, the government introduced the seized drugs and the
content of some of the wiretapped phone conversations into evidence.

        Although we ordinarily review a district court's factual findings in support of
its ruling on a motion to suppress for clear error, because Mr. West did not object to
the magistrate's findings of fact we review them for plain error only. United States v.
James, 

, 612 (8th Cir. 2003). But we subject the district court's legal
conclusions to de novo review regardless of whether objections are filed. Id.

                                          I.
      Mr. West contends that the district court should have suppressed the drugs
seized during a search of the residence that he shared with Kimberly Brown. The
fourth amendment generally requires a police officer to obtain a warrant based on
probable cause before entering or searching an individual's home, unless the attendant
circumstances establish a recognized exception to the requirement. See United States
v. Leveringston, 

, 1114 (8th Cir. 2005), cert. denied, 

(2005); U. S. Const. amend. IV. Mr. West does not challenge the existence of
probable cause, which was plainly present. He maintains, however, that the drugs
should have been suppressed because the officers did not obtain a warrant until after
they had conducted the search in issue. At the evidentiary hearing, the government


      2
       The Honorable Mary Ann L. Medler, United States Magistrate Judge for the
Eastern District of Missouri.

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and Mr. West offered conflicting evidence as to when the search occurred. After
noting internal inconsistencies in the accounts that Mr. West's witnesses gave, the
district court credited the testimony of a detective on the scene who testified that the
officers waited until the warrant issued before conducting the search. A district court's
assessment of witness credibility is "virtually unreviewable on appeal." United States
v. Heath, 

, 1275 (8th Cir. 1995), cert. denied, 

 (1995). We
detect no error, plain or otherwise, in the court's finding that the search was conducted
after the police obtained a warrant.

       Mr. West's alternative argument is that the evidence is inadmissible because the
officers entered the house illegally. Although the police admittedly entered the
residence before they had a warrant, the district court found on a sufficient record that
Ms. Brown had voluntarily consented to their entry. See Schneckloth v. Bustamonte,

, 222 (1973); United States v. Spotted Elk, 

, 652 (8th
Cir.2008). Nor was there any evidence that Ms. Brown ever withdrew her consent.
See United States v. Parker, 

, 1002 (8th Cir. 2005). The officers' entry
was legal because Ms. Brown consented to it, and so we need not reach Mr. West's
contention that an illegal entry would have rendered the evidence inadmissible, but
see Segura v. United States, 

 (1984).

                                            II.
       Mr. West also moved to suppress the content of phone conversations that the
government intercepted by wiretapping the phone that he used. He argues first that
the government failed to present sufficient evidence to meet the so-called necessity
requirement of 18 U.S.C. § 2518: When applying for wiretap authorization, the
government must explain fully what investigative procedures "have been tried and
failed or why they reasonably appear unlikely to succeed if tried or to be too
dangerous," 18 U.S.C. § 2518(1)(c), and, before granting an application, the court
must find that "normal investigative procedures" have failed or "reasonably appear to
be unlikely to succeed if tried or to be too dangerous," 18 U.S.C. § 2518(3)(c). Here,

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the district court3 that authorized the wiretap concluded that the government had made
the requisite showing of necessity, a factual finding that we review for clear error.
United States v. Jackson, 

, 644 (8th Cir. 2003); see United States v.
Thompson, 

, 859 (8th Cir.2000).

       The government attached to its application a sixty-one page affidavit signed by
Special DEA Agent Brendan Moles that detailed the government's use of other
investigative techniques, including surveillance, confidential informants, and
telephone pen registers (mechanical devices that record numbers called, but not the
content of conversations, on non-disposable phones). Agent Moles also explained
why other techniques, such as grand jury subpoenas and undercover agents, would
have been ineffective or dangerous in the circumstances. Although the government
had obtained a significant amount of information about the extensive drug operation
in which Mr. West was a primary player, the agent attested that normal investigative
procedures had not uncovered the sources of the cocaine in which he dealt.

       "If law enforcement officers are able to establish that conventional investigatory
techniques have not been successful in exposing the full extent of the conspiracy and
the identity of each coconspirator, the necessity requirement is satisfied." Jackson,
345 F.3d at 644. Given the detailed facts contained in Agent Moles's affidavit, which
the authorizing court was free to credit, we conclude that there is no clear error in the
finding that the government met the necessity requirement for a wiretap.

      We see no merit, moreover, in Mr. West's contention that the statutory regime
governing wiretaps requires the wiretap evidence gathered here to be suppressed
because federal agents did not "minimize the interception of communications" by
ceasing to record or listen to conversations that were unrelated to the drug


      3
        The Honorable Rodney W. Sippel, United States District Judge for the Eastern
District of Missouri.

                                          -4-
investigation. 18 U.S.C. § 2518(5); see 18 U.S.C. § 2515. Section 2518(5) "does not
forbid the interception of all nonrelevant conversations, but rather instructs the agents
to conduct the surveillance in such a manner as to 'minimize' the interception of such
conversations." Scott v. United States, 

, 140 (1978). We assess whether
the government violated the statute by determining whether the government's actions
were objectively reasonable in light of the particular circumstances. See id. at 137-38;
United States v. Padilla-Pena, 

, 462 (8th Cir. 1997). The district court's
determination that the government acted reasonably is a factual finding, id. at 462, that
we review for plain error in this case.

       Here, the court order that authorized the wiretap required the government to
minimize intercepted calls. The participating government agents were aware of the
minimization requirement and were trained in its implementation; before the wiretap
began, the agents signed documents confirming that they understood how to perform
the necessary minimization. Mr. West's argument relies principally on the fact that
the agents minimized only a small percentage of his many calls, but that does not
establish that they acted unreasonably; we must consider all the relevant
circumstances. See Scott, 436 U.S. at 140. The agents here were wiretapping a
primary figure in a cocaine distribution network and were therefore likely to intercept
many calls that pertained to that operation. Cf. id. And Mr. West presented no
evidence showing that calls that should have been minimized were not. We conclude
therefore that the district court did not plainly err in finding that the government's
conduct was objectively reasonable and thus we uphold its denial of the suppression
motion.

      We affirm the judgment of the district court.
                      ______________________________




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