United States Court of Appeals
                            FOR THE EIGHTH CIRCUIT
                                   ___________

                                   No. 03-4035
                                   ___________

United States of America,               *
                                        *
             Appellee,                  *
                                        * Appeal from the United States
      v.                                * District Court for the
                                        * District of Nebraska.
Rafael Beltran-Arce,                    *
                                        *
             Appellant.                 *
                                   ___________

                             Submitted: June 15, 2004
                                Filed: July 28, 2005
                                 ___________

Before SMITH, BEAM, and COLLOTON, Circuit Judges.
                           ___________

SMITH, Circuit Judge.

       A jury found Rafael Beltran-Arce guilty of several federal drug crimes alleged
in a four-count indictment, and he was sentenced to 235 months' imprisonment.
Beltran-Arce appeals the district court's refusal to grant a mistrial based on his
allegation that the government was permitted to introduce improper expert witness
testimony at trial. We affirm Beltran-Arce's convictions, but reverse and remand for
resentencing.

                                      I.
     The issues presented in this appeal concern the trial testimony of Sergeant
Langan of the Omaha Police Department. The government called Sergeant Langan
in its case-in-chief to provide expert testimony relating to drug conspiracies in the
Omaha area and typical drug record-keeping procedures. Before permitting Sergeant
Langan to testify, the district court conducted a hearing pursuant to Fed. R. Evid.
104(b).1 Ultimately, over Beltran-Arce's objections, Sergeant Langan was permitted
to testify as an expert regarding the modus operandi of local drug dealers. During his
testimony, Sergeant Langan opined that much of the methamphetamine coming into
Omaha originated in Mexico. The prosecution did not give Beltran-Arce proper Rule
16(a)(1)(G) notice regarding this type of testimony. Beltran-Arce moved for a
mistrial, arguing that the reference to Mexico was unduly prejudicial. The district
court denied the motion for mistrial and offered a curative instruction to the jury.

                                            II.
       First, Beltran-Arce asks us to revisit the district court's initial decision allowing
Sergeant Langan to offer general opinions about criminal drug activity and to
interpret notes—that the government argued were drug records—found in a notepad
seized from Beltran-Arce's residence. We review Beltran-Arce's claim that the district
court erred in allowing Langan's expert testimony under an abuse of discretion
standard. United States v. Molina, 

, 1056 (8th Cir. 1999).


      We begin our analysis by noting that a district court has "broad discretion to
allow law enforcement officials to testify as experts concerning the modus operandi

       1
       Beltran-Arce states that he "filed a Motion in Limine to exclude Sergeant
Langan's testimony." However, the record on appeal shows only a verbal objection
to the government's intention to call Sergeant Langan as an expert witness.
Interestingly, the district court does make references to Beltran-Arce's motion in
limine, which supports the hypothesis that the district court considered Beltran-Arce's
verbal objections as motions in limine. Nevertheless, we will accept that the issue was
presented and addressed below and thus properly preserved for appellate review.



                                            -2-
of drug dealers in areas concerning activities which are not something with which
most jurors are familiar." United States v. Sarabia-Martinez, 

, 452 (8th
Cir. 2002) (citing 

(8th Cir. 1999)). Federal Rule of
Evidence 7022 permits a district court to allow testimony of a witness whose
knowledge, skill, training, experience, or education will assist the trier of fact in
understanding an area involving specialized subject matter. 

.


       The district court considered Sergeant Langan's twenty-five years of service as
a police officer, his seventeen years in the Narcotics Unit, his fifteen years as a
supervisor in the Narcotics Unit, the number of training sessions and seminars in
narcotics investigations he has attended, the articles he has authored for law-
enforcement journals, his service as an instructor in narcotics investigations at
different training academies, and the fact that he has testified as an expert witness in
federal and state courts over one hundred times. We are convinced that the district
court's determination as to Sergeant Langan's expert-witness status was proper under
Rule 702.




      2
          Federal Rule of Evidence 702 states:

              If scientific, technical, or other specialized knowledge will
              assist the trier of fact to understand the evidence or to
              determine a fact in issue, a witness qualified as an expert
              by knowledge, skill, experience, training, or education,
              may testify thereto in the form of an opinion or otherwise
              if, (1) the testimony is based upon sufficient facts or data,
              (2) the testimony is the product of reliable principals and
              methods, and (3) the witness has applied the principals and
              methods reliably to the facts of the case.

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                                          III.
      Second, Beltran-Arce alleges that Sergeant Langan's testimony was unduly
prejudicial and erroneously led the jury to conclude that Beltran-Arce was keeping
drug records. Beltran-Arce specifically objects to the testimony Sergeant Langan
offered regarding a seized notepad. Sergeant Langan testified that it contained
possible drug notes because numbers on the pad corresponded to certain drug
quantities commonly sold on the streets. Sergeant Langan testified that 250 is a
common amount associated with the sale of a quarter ounce of methamphetamine or
cocaine and that 900 could be an amount associated with an ounce sale of cocaine.


      Langan's testimony, even as it related to the numerical notations, was limited
to his specialized knowledge that assisted the jury in its understanding of the
evidence and aided the jury to determine facts at issue. Therefore, the probative value
of Sergeant Langan's testimony substantially outweighed the danger of unfair
prejudice, confusion of the issue, or misleading the jury. United States v. Martinez,

, 1010 (8th Cir. 2004). Because Sergeant Langan's testimony was
relevant to show knowledge, and the probative value of the testimony was not
substantially outweighed by any danger of unfair prejudice, the district court did not
abuse its discretion by allowing the expert testimony. 

Beltran-Arce argues that the prosecution failed to follow the notification
requirements of Fed. R. Crim. P. 16(a)(1)(G), and the district court erred in its denial
of a mistrial based on the government's Rule 16 violations. We review a district
court's denial of a motion for mistrial for an abuse of discretion. United States v.
Boyd, 

, 983 (8th Cir. 1999).




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       Federal Rule of Criminal Procedure 16 (a)(1)(G) requires that the government
give the defendant a written summary of any expert testimony that the government
intends to use under Rules of Evidence 702, 703, or 705 during its case-in-chief at
trial. The summary must describe the witness's opinions, the bases and reasons for
those opinions, and the witness's qualifications.


      Here, in reference to Rule 16, the district court stated:


      It seems to me that Rule 16(a)(1)(G) is a rule that is generally not very
      well adhered to in this jurisdiction. It seems to me that it ought to be. It's
      a reasonable request, by the defendant and is one that would be required
      certainly in civil cases. And the purpose of the rule, generally speaking,
      is to give the opponent an opportunity to know the testimony of the
      expert witness in advance and then to be able to make a determination
      whether deposition testimony ought to be taken or a counter-expert
      should be retained.


      The difficulty is in our practice that the request, quote unquote, is made
      at the time of arraignment and certainly at the time of the arraignment
      government's counsel hasn't developed his trial strategy. So then the
      issue is when is a reasonable time that the government should provide
      this information to defense counsel?


      That issue has really never been broached in this jurisdiction as far as
      I'm aware. This is the first time that it has come up at least in my court.
      There's a progression order entered by the magistrate judge and I suspect
      that it doesn't have any such deadlines in it. Can either of you tell me
      whether it does?


      As predicted by the district court, the progression order failed to address expert
witness disclosure deadlines. In order to remedy this understandable omission, the


                                           -5-
district court "tr[ied] to figure out what a reasonable time [would be]." The court's
remedy was to require the government to provide the defense with a written summary
within twenty-four hours after Beltran-Arce lodged his Rule 16 discovery request.
The district court deemed the government's first attempt at compliance insufficient
to satisfy the requirements of Rule 16. Indeed, the district court required the
government to file three amendments to the summary before ruling that it was
sufficient.


       We are satisfied that the government's written summary in the original notice
(and the three amended notices), which provided Beltran-Arce with a summary of the
witness's qualifications, his opinions, and the basis supporting his opinions, was
adequate to meet the notice deadlines imposed by Rule 16. However, our Rule 16
inquiry continues.


      We next turn to Beltran-Arce's contention that Sergeant Langan's actual trial
testimony went beyond the scope of the Rule 16 summary provided by the
government. Sergeant Langan's testimony was mostly routine and substantially
tracked the summary report. However, the government did not disclose to Beltran-
Arce that Sergeant Langan would testify that most methamphetamine comes into
Omaha from Mexico.3 After this comment, the district court offered a cautionary


      3
          The reference to Mexico was made in the following context:

      Q [Mr. Cryne]. . . . Can you explain how a typical distribution chain
      would operate?

      A [Sergeant Langan]. Typically the present situation in Omaha is this.
      The vast majority of meth coming into Omaha is coming up from the
      Country of Mexico into California –

      Mr. O'Connor: Judge, I need a sidebar.

                                         -6-
instruction to the jury. Beltran-Arce claims this cautionary instruction could not erase
the "ethnic slant" that the government improperly utilized at trial. Beltran-Arce insists
that this undisclosed testimony prejudiced his case to such a degree that a mistrial
should have been ordered. We disagree.


       Sergeant Langan's unsolicited mention of Mexico, albeit improper, was an
isolated statement. The district court promptly addressed Beltran-Arce's objection and
gave a curative instruction to the jury. The district court "is in a far better position to
weigh the effect of improper testimony." United States v. Davidson, 

,
538 (8th Cir. 1997). As we have oft stated, "less drastic measures such as a cautionary
instruction are generally sufficient to alleviate prejudice flowing from improper
testimony." 

made no additional use of Sergeant Langan's
undisclosed comment. Accordingly, we find that the curative instruction was an
adequate remedy and the district court did not abuse its discretion in its decision not
to order the more drastic remedy of mistrial.


                                    V. Booker Error
      Beltran-Arce also attacks his sentence under United States v. Booker, 125 S.
Ct. 738 (2005). In Booker, the United States Supreme Court held, in part, that "[a]ny
fact (other than a prior conviction) which is necessary to support a sentence
exceeding the maximum authorized by the facts established by a plea of guilty or a
jury verdict must be admitted by the defendant or proved to a jury beyond a
reasonable 

. Beltran-Arce argues that his sentence violates
Booker because the court made factual findings concerning the quantity of drugs and
whether he possessed a firearm during the commission of at least one offense.
Beltran-Arce did not, however, object to the factual assertions made in the
presentence investigation report ("PSR"). "[A] fact in the PSR not specifically
objected to is admitted for purposes of Booker." United States v. McCully, 

, 933 (8th Cir. 2005) (citing Fed. R. Crim. P. 32(i)(3)).

                                           -7-
       While there was no constitutional Booker error, by applying the Guidelines as
mandatory rather than advisory, the district court made a non-constitutional Booker
error. See United States v. Henderson, 408 F.3d 1078,79 (8th Cir. 2005). Beltran-
Arce failed to argue for an advisory application of the Guidelines, and, thus, we
review for plain error. United States v. Pirani, 

, 550 (2005) (en banc).
Under our plain error analysis, Beltran-Arce is required to show "a 'reasonable
probability,' based on the appellate record as a whole, that but for the error he would
have received a more favorable sentence" to show that his substantial rights were
affected. 

(applying the third prong of the plain error test found in United
States v. Olano, 

(1993)).


      The Guidelines range for Beltran-Arce was between 235–293 months'
imprisonment. At the sentencing hearing, counsel argued that even the low end of the
Guidelines was unfair and improper under the facts and circumstances of Beltran-
Arce's case. The court explained that, while it would like to grant a downward
departure, it was not allowed under the Guidelines. Accordingly, the district court
sentenced Beltran-Arce to the lowest possible sentence under the Guidelines, 235
months.


       The fact that Beltran-Arce was sentenced at the bottom of the Guidelines range
"is insufficient, without more, to demonstrate a reasonable probability that the court
would have imposed a lesser sentence absent the Booker error." United States v.
Pirani, 

, 553 (8th Cir.2005). However, in this case, the record indicates
that the court would have given Beltran-Arce a lesser sentence had the Guidelines not
been mandatory. We are satisfied that there is a reasonable probability that the court
would have imposed a lesser sentence had it viewed the Guidelines as advisory in
conjunction with the factors listed in 18 U.S.C. § 3553(a). The record indicates that,
based on Betlran-Arce's factual situation, the district court was not content with

                                         -8-
recommended Guidelines range, and affirming the sentence despite the district court's
erroneous belief that the Guidelines were mandatory would "seriously affect[ ] the
fairness, integrity, or public reputation of judicial proceedings." See United States v.
Rodriguez-Ceballos, 

, 941–942 (8th Cir. 2005) (citations omitted). We
recognize that "there may be plain Booker errors that meet the third Olano factor but
not the fourth," 

; however, we are persuaded that in this case
Beltran-Arce has satisfied the fourth prong.


      For the foregoing reasons, we affirm Beltran-Arce's convictions, but reverse
and remand for resentencing.
                        ______________________________




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