United States Court of Appeals
                            FOR THE EIGHTH CIRCUIT
                                    ___________

                                    No. 02-2679
                                    ___________

United States of America,           *
                                    *
      Plaintiff - Appellee,         *
                                    * Appeal from the United States
      v.                            * District Court for the
                                    * Northern District of Iowa.
Donald Lee Houston, also known as   *
Pete Houston,                       *
                                    *
      Defendant - Appellant.        *
                               ___________

                              Submitted: March 12, 2003

                                   Filed: August 5, 2003
                                    ___________

Before HANSEN,* Chief Judge, LOKEN and MURPHY, Circuit Judges.
                              ___________

LOKEN, Chief Judge.

     Donald Lee Houston pleaded guilty to manufacturing, attempting to
manufacture, and aiding and abetting the manufacture of five or more grams of actual
methamphetamine in violation of 21 U.S.C. §§ 841(a)(1) and 841(b)(1)(B). Houston
now appeals his sentence, arguing the district court clearly erred in finding that he is


      *
       The Honorable David R. Hansen stepped down as Chief Judge at the close of
business on March 31, 2003. The Honorable James B. Loken became Chief Judge
on April 1, 2003.
accountable for more than 50 but less than 150 grams of actual methamphetamine,
which resulted in a base offense level of 32. The issue on appeal, one of first
impression, is whether the government proved that the methamphetamine quantities
Houston admitted he helped manufacture were “actual” methamphetamine quantities,
rather than mixture quantities. In reviewing the drug quantity finding for clear error,
we must affirm unless the entire record firmly convinces us that a mistake has been
made. See United States v. Moore, 

, 446 (8th Cir. 2000). Concluding
that the issue was properly preserved in Houston’s objections to the Presentence
Investigation Report (PSR), and entirely ignored in the government’s proof at
sentencing, we reverse.

                               I. Framing the Issue

      For drug manufacturing offenses, the Sentencing Guidelines provide that a
defendant’s base offense level is based upon drug quantity. U.S.S.G. § 2D1.1(a)(3).
The Drug Quantity Table in § 2D1.1(c) specifies the base offense levels for various
quantities of the most common illegal drugs. For only three drugs -- PCP,
methamphetamine, and amphetamine -- the Table lists alternative quantities for each
offense level. For example, the Table places the following quantities in Level 32:

      At least 500 G but less than 1.5 KG of Methamphetamine, or at least 50
      G but less than 150 G of Methamphetamine (actual) . . . .

§ 2D1.1(c)(4). The commentary to § 2D1.1 then explains:

      The term[] . . . “Methamphetamine (actual)” refer[s] to the weight of the
      controlled substance, itself, contained in the mixture or substance. For
      example, a mixture weighing 10 grams containing [methamphetamine]
      at 50% purity contains 5 grams of [methamphetamine] (actual). In the
      case of a mixture or substance containing . . . methamphetamine, use the
      offense level determined by the entire weight of the mixture or

                                         -2-
      substance, or the offense level determined by the weight of the . . .
      methamphetamine (actual), whichever is greater.

§ 2D1.1, comment. n.(B) to Drug Quantity Table (emphasis added). As the above-
quoted Level 32 entry illustrates, the alternative quantities for each base offense level
in the Table comprise a 10:1 ratio, the same ratio codified by Congress in the
mandatory minimum penalty provisions applicable to methamphetamine offenses.
See, e.g., 21 U.S.C. § 841(b)(1)(A)(viii).

       The government bears the burden of proving drug quantity by a preponderance
of the evidence. See United States v. Hollingsworth, 

, 703 (8th Cir.
2002), cert. denied, 

(2003). When use of the actual
methamphetamine alternative produces a greater sentence, the government must
prove the actual methamphetamine content of the substance or substances in question.
See United States v. Bogusz, 

, 87 (3d Cir. 1994). The government may
prove the total quantity of actual methamphetamine in a series of transactions by
testing the purity of a seized quantity and applying the percentage of actual
methamphetamine in the tested quantity to the unrecovered quantities. See United
States v. Newton, 

, 614 (8th Cir. 1994); accord United States v. Lopes-
Montes, 

, 731-32 (9th Cir. 1999). When no quantity has been recovered,
the government may prove the purity of quantities attributed to the defendant by
circumstantial evidence, for example, a conspirator’s reliable testimony that
purchased methamphetamine was “undiluted, unadulterated . . . not cut . . . pure,”
United States v. Cockerill, 

, 

at **1 (4th Cir. 2000)
(unpublished per curiam), or an expert’s testimony as to the normal purity of
methamphetamine produced in a lab, see United States v. Mosby, 

,
1071 (8th Cir. 1999).

      As with all fact-intensive sentencing issues, if the defendant makes a timely
objection to the drug quantity determination in the PSR, “if the sentencing court

                                          -3-
chooses to make a finding with respect to the disputed facts, it must do so on the basis
of evidence, and not the presentence report.” United States v. Hudson, 

,
995 (8th Cir. 1997) (quotation omitted).

                     II. The Sentencing Record in This Case

       The determination of drug quantity in this case began, as it usually does, with
the factual recitations in the PSR. The PSR set forth two alternative ways to calculate
the total quantity of methamphetamine attributable to Houston. First, paragraph 32
of the PSR assessed “a total of 212.6 grams of methamphetamine (actual).” This total
quantity was based upon (i) Houston’s admission that he had manufactured “½ to ¾
ounce of actual methamphetamine” with co-defendant Chad Curley on five or six
occasions, resulting in 70.85 grams of actual methamphetamine (PSR paragraph 28);
and (ii) Houston’s admission that he allowed Kevin Demoss to manufacture one
ounce of methamphetamine on Houston’s property on four or five occasions,
resulting in an additional 141.75 grams of actual methamphetamine (PSR paragraph
31). Based upon this 212.6 gram finding, the PSR recommended a base offense level
of 34 (more than 150 but less than 500 grams of actual methamphetamine).

       In his PSR objections, Houston denied the quantities alleged in paragraph 28
and alleged that he had “nothing to do with” the activities of Demoss alleged in
paragraph 31. In addition, Houston objected to the assessment of 212.6 grams of
actual methamphetamine in paragraph 32 of the PSR, stating that the correct total
quantity is 56 grams and “the Base Offense Level should not be 34 but should be
Level 26.” The Drug Quantity Table places a total quantity of 56 grams of
methamphetamine mixture in Level 26. See § 2D1.1(c)(7) (“[a]t least 50 G but less
than 200 G of Methamphetamine, or at least 5 G but less than 20 G of
Methamphetamine (actual).” Thus, Houston’s objections to the PSR clearly raised
the actual methamphetamine issue. The sentencing hearing transcript confirms that
the district court understood this was a contested issue.

                                          -4-
      Alternatively, paragraph 32 of the PSR calculated total drug quantity by
assessing 814.35 grams of methamphetamine mixture. This quantity was based
primarily upon “laboratory reports” that officers recovered 671 grams in a warrant
search of Houston’s home in November 2001. This alternative quantity produced a
base offense level of 32. In his objections, Houston denied “any involvement with
the substance” and denied “that this mixture could have made methamphetamine.”
At sentencing, the government offered no proof regarding what was recovered in the
search of Houston’s home. Therefore, we may not uphold the district court’s base
offense level finding by this alternative method.

      At the sentencing hearing, the government relied upon the testimony of Iowa
Division of Narcotics Enforcement Officer Gregory Brugman to prove the actual
methamphetamine drug quantity set forth in the PSR. Agent Brugman testified:

      Q. Okay. What did the defendant tell you about manufacturing
      methamphetamine?

      A. He stated -- we initially talked to him about Chad Curley and he
      stated he had helped Mr. Curley on approximately five to six occasions
      when he manufactured methamphetamine.

                               *    *   *     *   *

      Q. Did he tell you what quantity or approximately what quantity of
      methamphetamine they cooked each time?

      A. He stated he was cooking approximately a half ounce to three-
      quarters of an ounce quantity of methamphetamine on each occasion.

Later in his direct testimony, Agent Brugman was asked about Houston’s admissions
regarding Kevin Demoss:



                                        -5-
      Q. What did he tell you about that date?

      A. He stated that Chad Curley had come out to the farm along with his
      cousin, Keven Demoss, and at that time they had done a one ounce cook
      of methamphetamine.

                                *    *   *     *   *

      Q. Did he give you any more information about this Kevin Demoss and
      cooking methamphetamine?

      A. Yes, he did.

      Q. What did he say about him?

      A. He stated that Kevin Demoss and his wife Dawn lived in his
      farmhouse with [Houston] and his wife and they were there
      approximately two or three months, and during that time he witnessed
      them cook methamphetamine at his residence.

                                *    *   *     *   *

      Q. Did the defendant receive anything for allowing those [cooks] to
      happen on his property?

      A. Yes, he did.

      Q. What did he receive?

      A. He was getting anywhere from two grams of methamphetamine up
      to an eighth ounce of methamphetamine.

      The district court credited Agent Brugman’s testimony in finding that Houston
helped Curley produce 70.85 grams of actual methamphetamine. After reducing the
quantity attributable to the Demoss cooks that Houston assisted, the court found that
Houston was responsible for a total of less than 150 grams of actual

                                         -6-
methamphetamine, rather than the 212.6 grams calculated in the PSR, and therefore
found that his base offense level is 32.

                                   III. Discussion

       The district court properly relied on Houston’s admissions in estimating drug
quantity. The court believed Agent Brugman’s testimony regarding those admissions,
rather than Houston’s vague testimony at the sentencing hearing that his quantity
“guesstimates” were overstated. That credibility determination is virtually
unreviewable on appeal. See United States v. Behler, 

, 1273 (8th Cir.),
cert. denied, 

(1994). Thus, the district court’s quantity finding is well-
supported. The issue is whether the government proved that the quantities to which
Houston admitted were actual methamphetamine, rather than a mixture.

        In reviewing this issue, we conclude it is critical that Agent Brugman testified
that Houston admitted to helping manufacture methamphetamine, not actual
methamphetamine. At no point did government counsel ask Brugman, an
experienced drug investigator, whether Houston ever referred to actual or pure
methamphetamine. Nor did counsel ask Brugman whether he understood Houston
to be referring to quantities of actual methamphetamine. Likewise, when Houston
testified for the defense and asserted that the methamphetamine he helped Curley
manufacturer was low quality (“filth”), government counsel did not ask on cross
examination whether the quantity estimates he gave Agent Brugman referred to the
total weights of the substances manufactured by Curley and Demoss, or to Houston’s
estimate of the net weight of the methamphetamine contained in those substances.

        Agent Brugman’s testimony was the government’s entire case at sentencing on
the issue of actual methamphetamine quantity. None of the methamphetamine
manufactured by Curley and Demoss was recovered and tested for purity. No expert
testified as to the typical purity of methamphetamine manufactured in these

                                          -7-
quantities, by this method, and in these conditions. Agent Brugman admitted that two
samples attributed to Houston -- not necessarily end products of the Curley and
Demoss cooks -- had been tested and found to be methamphetamine mixtures. (The
lab reports of these tests were not made part of the record on appeal, and Agent
Brugman was not asked what purity data was reported.)

       On this record, we can only conclude that the district court, like the author of
the PSR, simply assumed that the quantities Houston admitted to Agent Brugman
were actual methamphetamine quantities. We think the assumption unwarranted.
When a lay person is asked in general terms how much methamphetamine he helped
someone else cook, his answer will almost certainly be in terms of the size of the
resulting mixture, not the net weight of one of its components. Government counsel
probably knew that; in any event, he did not address this critical issue in questioning
Agent Brugman and Houston at the sentencing hearing. The result is a record that has
no evidence supporting the quantity finding of more than 50 grams of actual
methamphetamine. The quantity itself is supported, but the finding that it was actual
methamphetamine is clearly erroneous.

      Relying upon Agent Brugman’s testimony that methamphetamine cooks
attempt to produce pure methamphetamine, the government argues that a base offense
level of 32 is warranted even if Houston’s admissions reflected total quantities
produced by Curley and Demoss, rather than the net weight of the methamphetamine
contained in those substances. The government cites no authority for this contention,
and we reject it. Note (B) to the Drug Quantity Table defines actual
methamphetamine as “the weight of the controlled substance, itself, contained in the
mixture.” (Emphasis added.) Congress and the Sentencing Commission have
mandated alternative methods for determining total quantities of methamphetamine,
PCP, and amphetamine. The distinction would be obliterated if the total quantity of




                                         -8-
every batch of methamphetamine was deemed to be actual methamphetamine because
the cook hoped or attempted to produce the drug in its pure form.1

       The record is devoid of any evidence to justify a finding of at least 50 grams
of actual methamphetamine, or 500 grams of a methamphetamine mixture, the
minimum alternative quantities necessary to place Houston’s offense in base offense
level 32. Accordingly, the judgment of the district court is reversed and the case is
remanded for resentencing on the existing sentencing record.2

      A true copy.

             Attest:

                CLERK, U. S. COURT OF APPEALS, EIGHTH CIRCUIT.




      1
        In footnote 33 of its November 1999 Final Report on Methamphetamine, the
Sentencing Commission reported: “DEA information indicates that purity of
trafficked methamphetamine has exceeded 50 percent in recent years . . . . The DEA
has reported that most recently the purity of methamphetamine has declined to below
30 percent.” See also United States v. Eide, 

, 703-04 (8th Cir. 2002).
      2
         In addition to the drug offense discussed in this opinion, Houston pleaded
guilty to being a felon in possession of a firearm. The district court imposed
concurrent sentences of 156 months in prison for the drug offense and the statutory
maximum of 10 years (120 months) in prison for the felon-in-possession offense. On
remand, we do not preclude the court from resentencing on the firearm count, for
example, should Houston’s new sentence for the drug offense fall below the statutory
maximum sentence of 10 years for the firearm offense which was imposed at the
initial sentencing.

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