In the
 United States Court of Appeals
              For the Seventh Circuit
                        ____________
No. 05-2222
UNITED STATES OF AMERICA,
                                                Plaintiff-Appellee,

                               v.


ALTWAN D. CROSS,
                                            Defendant-Appellant.

                        ____________
           Appeal from the United States District Court
             for the Western District of Wisconsin.
          No. 04 CR 179—Barbara B. Crabb, Chief Judge.
                        ____________
  ARGUED SEPTEMBER 26, 2005—DECIDED NOVEMBER 23, 2005
                        ____________



  Before EASTERBROOK, RIPPLE and ROVNER, Circuit Judges.
  RIPPLE, Circuit Judge. On January 27, 2005, Altwan Cross
pleaded guilty to one count of possession with intent to
distribute 500 grams or more of a substance containing
cocaine. See 21 U.S.C. § 841(a)(1). He was sentenced to 150
months in prison. See 

Mr. Cross now
challenges his sentence; he alleges that the district court
violated the Ex Post Facto Clause of the Constitution of the
2                                                 No. 05-2222

United States by applying retroactively the remedial portion
of United States v. Booker, 

(2005). He also
contends that the district court erred in calculating the
quantity of drugs for which he was liable at sentencing.
Because Mr. Cross’ ex post facto argument was considered
and rejected in United States v. Jamison, 

(7th Cir.
2005), and because the district court did not plainly err in
crediting sentencing hearing testimony that established the
defendant’s involvement in the distribution of more than
five kilograms of cocaine, we affirm the judgment of the
district court.


                               I
                      BACKGROUND
  During August 2004, the Dane County Narcotics and
Gang Task Force initiated an investigation into Mr. Cross’
drug trafficking activities. A confidential informant had told
investigators that he had been purchasing cocaine from Mr.
Cross for many years. As part of the investigation, the police
supervised four controlled purchases of cocaine from Mr.
Cross by the informant and an undercover agent. These
sales totaled approximately 150 grams and were made
during August, September and October of 2004. On October
19, 2004, a search warrant was executed at Mr. Cross’
residence. The police recovered $13,520 in U.S. currency and
nine individually wrapped baggies of white powder,
hidden in a nylon lunch bag. A digital scale and a bottle of
Pro Scent—a liquid used to dilute, and therefore increase
the quantity of, controlled substances—was also recovered.
Mr. Cross was present at the scene and arrested, as was his
girlfriend. The powder, which weighed a total of 1,083
grams, field-tested positive for the presence of cocaine. Mr.
No. 05-2222                                                  3

Cross subsequently admitted that the cocaine was his and
that the cash was proceeds from drug sales.
  On October 28, 2004, a grand jury in the Western District
of Wisconsin returned a one-count indictment charging Mr.
Cross with possession of and intent to distribute 500 or
more grams of cocaine, a Schedule II controlled substance,
in violation of 21 U.S.C. § 841(a)(1). He pleaded guilty to
this offense on January 27, 2005.
  The sentencing hearing was held on April 22, 2005. The
Government called two witnesses. First, Jerry McCoy, Jr., a
former friend and drug colleague of Mr. Cross, testified.
McCoy had been arrested in October 2004 for distribution of
cocaine, see 

to 27 years’ imprisonment. He
told the court that he had agreed to assist the Drug Enforce-
ment Administration (“DEA”), including testify-
ing against Mr. Cross, in the hope that his cooperation
would warrant a downward departure.
  McCoy testified that he had known Mr. Cross for between
three and five years. During that time, he also met Liborio
Prado-Morales, a local drug dealer. He later introduced this
individual to Mr. Cross for the purpose of conducting drug
transactions. The first such transaction, according to McCoy,
occurred in the spring of 2004 and consisted of the purchase
of one kilogram of cocaine by Mr. Cross from Prado-Mo-
rales. Over the course of the next few months, Mr. Cross and
McCoy purchased cocaine from Prado-Morales four or five
times. McCoy estimated that Mr. Cross bought one-half of
a kilogram on one occasion, a full kilogram three or four
times, and a kilogram-and-a-half once or twice. McCoy also
verified that, after his own arrest, he placed a monitored call
to Mr. Cross in which Mr. Cross expressed a desire to buy
cocaine from Prado-Morales later that week.
4                                                No. 05-2222

  The Government next called Detective Michael Montie of
the Madison Police Department. He testified that the police
had placed a tap and trace on McCoy’s cell phone in
February 2004, prior to his arrest. This monitoring revealed
more than 650 phone calls over the course of five months
between McCoy and Mr. Cross. A similar trace was also
placed on Mr. Cross’ phone; it revealed twenty-nine calls
during the month of September 2004 and seventeen calls
during October 2004 to Prado-Morales. A summary of the
results of the tap and traces on the phones of McCoy and
Mr. Cross was introduced into evidence.
   The Government also introduced the written testimony of
its confidential informant. Although the court noted that the
informant’s “credibility [was in] dispute” because of his
former felony convictions, R.37 at 6, it credited the testi-
mony as establishing that Mr. Cross had been selling
cocaine “for years,” including the sale of approximately
150 grams while under police surveillance in the late
summer and fall of 2004, 

   In his closing statement, counsel for Mr. Cross argued that
McCoy’s testimony—the only evidence substantiating with
any precision that Mr. Cross had possessed more than five
kilograms of cocaine—was unreliable. He pointed out that
McCoy had refused to answer a number of questions on
cross-examination, including how many prior convictions
were on his record; the nature and extent of his drug habit;
how many times he had purchased cocaine from Prado-
Morales; whether he had also purchased cocaine from his
brother; and whether he had assisted another individual in
filling out false financial statements.
  The defense also argued that McCoy’s testimony could not
be trusted because of his intimate involvement in the drug
trade and his criminal history, including allegedly assisting
No. 05-2222                                                  5

another individual in filling out false financial forms. In
support of this theory, the defense introduced the affidavit
of Montrell Savage, which described Savage’s troubled
history with McCoy related to cocaine trafficking. Specifi-
cally, Savage recounted that, when he tried to break off his
relationship with McCoy, he received threats and his cars
were vandalized. Savage also opined that, based
on his experiences, he did not believe McCoy to be a
“truthful person.” Def.’s Ex.2; see also R.37 at 29-30. Lastly,
the defense argued that McCoy’s testimony regarding the
quantity of cocaine purchased on each visit to Prado-
Morales was speculative: McCoy admitted that he did not
remember exactly how much cocaine Mr. Cross had pur-
chased, and that he could only estimate that, once or twice,
he purchased one kilogram, a few times a half of a kilogram,
and maybe once or twice a kilogram-and-a-half.
  Although it recognized that “McCoy had some credibility
problems,” 

the district court credited the specifics
of his testimony as it related to the quantity of cocaine
purchased by Mr. Cross from Prado-Morales. In the court’s
view, McCoy’s version of events was corroborated by other
evidence in the case, including the testimony of the confi-
dential informant, phone records from the tap and traces,
cash and cocaine found in Mr. Cross’ residence during the
October 2004 search, Mr. Cross’ prior arrests and the
exorbitant lifestyle he led despite his negligible income
reported on federal tax forms. The district judge concluded,
“[i]t would be just ridiculous to close my eyes to the evi-
dence in this case of Mr. Cross’s long, significant involve-
ment in the distribution of cocaine.” 

  The district court then calculated the advisory guidelines
sentencing range:
6                                                   No. 05-2222

    McCoy testified to five or six visits [to Prado-Morales].
    If I take five visits, if I say that on three of those visits
    Mr. Cross bought a half a kilo, one visit he bought a
    kilo, one visit he bought a kilo and a half, all of which
    Mr. McCoy testified, that’s four kilos. He had over a kilo
    that he doesn’t even contest. That takes us up to five
    kilos.1

determined by the court, the total quantity of
cocaine involved in Mr. Cross’ course of drug dealing was
over five kilograms; this amount warranted a base offense
level of 32. Taking into account a three-point downward
adjustment for acceptance of responsibility, Mr. Cross was
assigned an adjusted offense level of 29. His previous record
placed him in criminal history category of IV. Therefore, the
guidelines recommended a sentence of between 121-151
months in prison. The district court then imposed a sentence
of 150 months, which is at the higher end of this range.




1
  Absent McCoy’s testimony, Mr. Cross would have been
sentenced for possession of and intent to distribute only 500
grams of cocaine, which translates to a base offense level of 26.
Once three points are subtracted for acceptance of responsibility,
the adjusted offense level would have been 23 and the guidelines
range 71-87 months. See Presentence Report at 6. In light of
McCoy’s testimony, the Presentence Report was amended to
recommend a base offense level of 32, for the possession with
intent to distribute approximately 6.2 kilograms of cocaine, with
an advisory sentencing range of 168-210 months. The court
accepted the base offense level recommended in the amended
Presentence Report, but subtracted three points for acceptance of
responsibility, resulting in a sentencing range of 121-151 months.
No. 05-2222                                                  7

                              II
                       DISCUSSION
  Before this court, Mr. Cross appeals his sentence. He
submits that his sentence violates the Ex Post Facto Clause of
the Constitution. He further contends that the district
court’s finding that the total amount of cocaine attribut-
able to him was over five kilograms is clearly erroneous.


A. The Ex Post Facto Clause
  Mr. Cross contends that his sentence violates the Ex Post
Facto Clause of the Constitution. Specifically, he argues that
the retroactive application of the remedial portion of the
Supreme Court’s decision in United States v. Booker, 125 S.
Ct. 738 (2005), which held that the Sentencing Guidelines are
merely advisory and thus permits the district court to
sentence a defendant on the basis of facts neither found by
the jury nor stipulated to by the defendant, unconstitution-
ally exposes him to a longer maximum sentence.
  This position, however, was considered and rejected in
United States v. Jamison, 

(7th Cir. 2005). Jamison
held that the remedial portion of the Booker opinion could be
applied retroactively without constitutional difficulty
because the defendant was given “fair warning” that
distributing cocaine was punishable by “up to twenty years,
as spelled out in the United States Code.” 

The
doctrines of stare decisis and precedent counsel that we
should not revisit this matter. Because Mr. Cross has offered
no reason why Jamison does not control the outcome of this
case, we cannot accept the contention that his sentence
violates the Ex Post Facto Clause.
8                                                  No. 05-2222

B. Drug Quantity Calculations
    1. Standard of Review
  Mr. Cross also contends that McCoy’s testimony, relied on
by the district court in sentencing Mr. Cross for possession
of more than five kilograms of cocaine, is unreliable. We
review a district court’s calculation of the quantity of drugs
involved in an offense—a factual determination—for clear
error. United States v. Souffront, 

, 832 (7th Cir.
2003). We shall reverse the determination of the district
court only if, “after reviewing the entire record, we are left
with the firm and definite conviction that a mistake has
been made.” United States v. Brumfield, 

, 730 (7th
Cir. 2002) (quotation marks omitted).


    2. Discussion
  Mr. Cross submits that the district court based its conclu-
sion that he possessed and intended to distribute more than
five kilograms of cocaine on unreliable evidence, namely the
“incredible” testimony of McCoy. Appellant’s Br. at 4. He
emphasizes not only McCoy’s history of drug abuse, drug
dealing and criminal convictions, but also McCoy’s unwill-
ingness to answer a number of questions on cross-examina-
tion.
  Although we give great deference to a district court’s
factual findings concerning drug quantity, we also must “be
mindful of a defendant’s due process right to be sentenced
on the basis of reliable information.” 

; see also United States v. Garcia, 

, 856 (7th Cir.
1995). Because of this concern, “we have instructed district
courts to scrutinize more carefully certain types of evidence
offered at sentencing hearings.” 

;
see also United States v. Beler, 

, 1434-37 (7th Cir.
No. 05-2222                                                        9

1994). However, so long as the evidence “ ’bear[s] sufficient
indicia of reliability to support [its] probable accuracy,’ the
court may consider [it] in sentencing.” United States v.
Lanterman, 

, 161 (7th Cir. 1996) (citation omitted);
see also 

(holding that although the
witness’ testimony “contained some equivocations,” it was
not “so unreliable as to preclude the district court’s consid-
ering it in calculating [the sentence]”).
   Even though McCoy’s testimony contains ambiguities and
is marked by his unwillingness to answer certain questions,
we cannot conclude that these factors render the evidence so
unreliable as to preclude the district court from considering
it or even relying on it in calculating Mr. Cross’ sentence.2



2
  Mr. Cross’ situation is easily distinguishable from the circum-
stances in which we have determined that the evidence on which
the district court relied at sentencing was untrustworthy. For
example, in Beler, we held that the district had failed to conduct
a “sufficiently searching inquiry into the government’s evidence
to ensure its probable accuracy.” United States v. Beler, 

, 1433 (7th Cir. 1994). Not only did the court fail to probe
inconsistences between the witness’ two affidavits concerning
drug quantity, 

was never required to explain
under oath the discrepancy between his two estimates.”), but it
also failed to consider a “crucial variance” between the witness’
second affidavit and his testimony at trial, which rendered
uncertain the defendant’s “length of the course of dealing.” 

see also United States v. McEntire, 

, 437 (7th Cir.
1998) (holding that the evidence relied on by the district court
was unreliable, given that it was “uncorroborated and the district
court did not provide a rationale for believing one set of contra-
dictory statements over another”). Here, by contrast, the district
court carefully considered the deficiencies in McCoy’s testimony,
                                                     (continued...)
10                                                    No. 05-2222

To be sure, on cross-examination, McCoy refused to say
how many times he had purchased cocaine from Prado-
Morales; whether he also had purchased cocaine from his
brother; whether he had used cocaine on a regular basis;
and whether he had assisted another individual in filling
out false financial statements. But, even assuming that these
questions had been answered in the manner most favorable
to the defense, thus establishing that McCoy was a frequent
user of drugs and significantly involved in the drug trade,3
the district court did not act unreasonably in relying on his
testimony.
  A witness’ history of drug abuse does not necessarily
render his testimony unreliable or unworthy of consider-
ation. See 

. We note, moreover, that
there is no evidence that the witness’ memory was “im-
paired by ‘a history of cocaine addiction.’ ” United States v.
McEntire, 

, 437 (7th Cir. 1998) (citation omitted).
Nor is a witness’ history of drug dealing a disqualifying
factor. Especially when a defendant is charged with drug-


(...continued)
and credited that testimony despite defense counsel’s objections,
in light of the substantial evidence corroborating McCoy’s
account.
3
   Mr. Cross does not argue that McCoy’s refusal to answer these
questions violated his constitutional rights, such as his Sixth
Amendment right to confrontation. Instead, he argues that the
unanswered questions prove the witness to be unreliable:
specifically, that it makes it likely that McCoy was, in fact, a drug
user and dealer. Thus, we proceed as if the witness answered the
cross-examination questions in the manner most favorable to the
defense, and nevertheless conclude that the district court did not
err in crediting his testimony in the course of calculating Mr.
Cross’ sentence.
No. 05-2222                                                    11

related activities, the court cannot “expect members of the
cloth to testify about the intricacies of [the defendant’s] drug
dealing . . . operation.” United States v. 1948 S. Martin Luther
King Dr., 

, 1113 (7th Cir. 2001) (holding that the
district court did not err in finding that the “use of witnesses
who are cooperating and have criminal histories is not
unusual in this context”) (quotation marks omitted); see also

(noting that a district court may
“credit testimony that ‘is totally uncorroborated and comes
from an admitted liar, convicted felon, large scale drug-
dealing, paid government informant,’ ” so long as there is
“ ’sufficient indicia of reliability’ ”) (citations omitted);

(witness’ criminal background as a
drug dealer “does not by itself establish unreliability”).
  Here, the testimony of McCoy is bolstered by evidence
corroborating his version of events, including phone records
evidencing contact between Mr. Cross and Prado-Morales,
the money and drugs seized from Mr. Cross’ home, his prior
arrests for drug-related activity, and the confidential
informant’s testimony that he had been purchasing cocaine
from Mr. Cross for years and that he was able to make
controlled purchases from Mr. Cross in the fall of 2004 with
“ease.” R.37 at 54.
  In light of this evidence, which gives McCoy’s testimony
sufficient indicia of reliability, we cannot say that the district
court committed clear error in relying on McCoy’s testi-
mony. “Simply put, the district court had to make the type
of routine credibility determination inherent in the fact-
finding process.” 

; see also United
States v. Torres-Ramirez, 

, 980-81 (7th Cir. 2000)
(“When the sentence rests on testimony under oath . . . it is
enough that the judge believe the witness—unless the
testimony is illogical or contradicted by documents or other
12                                                No. 05-2222

physical evidence, making it clearly erroneous to accept the
witness’s version of events.”); United States v. Roe, 

, 749 (7th Cir. 2000) (holding that appellate courts shall
not disturb a lower court’s “credibility determinations,”
given that the lower court is “in the best position to observe,
weigh, and evaluate a witness’ verbal as well as nonverbal
behavior”) (citation omitted). After hearing McCoy’s
testimony, observing his demeanor, listening to defense
arguments concerning the factors affecting McCoy’s credi-
bility and assessing the other evidence in the case, the
district court was entitled to accept McCoy’s version of the
events and to sentence Mr. Cross for possession with intent
to distribute more than five kilograms of cocaine.


                         Conclusion
  For the foregoing reasons, the judgment of the district
court is affirmed.
                                                    AFFIRMED
A true Copy:
        Teste:

                           _____________________________
                            Clerk of the United States Court of
                              Appeals for the Seventh Circuit




                    USCA-02-C-0072—11-23-05