FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                  No. 06-50684
                Plaintiff-Appellee,
               v.                            D.C. No.
                                          CR-06-00468-RTB
DAVID BERBER-TINOCO,
                                             OPINION
             Defendant-Appellant.
                                      
       Appeal from the United States District Court
          for the Southern District of California
        Roger T. Benitez, District Judge, Presiding

                 Argued and Submitted
        September 27, 2007—Pasadena, California

                 Filed December 19, 2007

    Before: J. Clifford Wallace, Thomas G. Nelson, and
               Sandra S. Ikuta, Circuit Judges.

                  Opinion by Judge Ikuta




                           16531
16534          UNITED STATES v. BERBER-TINOCO


                        COUNSEL

James Fife, Federal Defenders of San Diego, Inc., San Diego,
California, for the defendant-appellant.

David D. Leshner, Assistant United States Attorney, Office of
the United States Attorney, San Diego, California, for the
plaintiff-appellee.
                UNITED STATES v. BERBER-TINOCO            16535
                          OPINION

IKUTA, Circuit Judge:

   We consider the challenge brought by David Berber-
Tinoco to the district court’s denial of his motion to suppress.
Berber sought to suppress his statements and fingerprints
which were taken pursuant to an arrest by Border Patrol offi-
cers. Berber argues that the officers lacked reasonable suspi-
cion to stop him, and also argues that we must reverse the
district court’s ruling due to misconduct by the district court
judge during the suppression hearing. We hold that there was
reasonable suspicion for the stop and that the judge’s viola-
tion of Rule 605 of the Federal Rules of Evidence was harm-
less. Therefore, we affirm.

                               I

   Around 10:30 on the night of February 9, 2006, Border
Patrol Officers Thomas Englehorn and Robert Lenoir were
positioned in their vehicles at different spots on Lyons Valley
Road between Honey Springs and Japatul Valley Road. This
area is completely rural with no residences and no businesses
other than a juvenile detention center and a fire station. Two
hours earlier, a seismic intrusion device had been activated.
Based on their experience, the officers knew that it would
take an alien crossing the border approximately two hours to
get to this site, which was a notorious smuggling area with
known load sites for aliens.

   From his position at the Japatul Fire Station off of Lyons
Valley Road, Officer Engelhorn saw two vehicles, a Dodge
Durango and a Ford pickup truck, approach the area. Already
on the look-out for smuggling because of the alarm from the
seismic intrusion device, Officer Engelhorn became suspi-
cious when he observed the two vehicles driving “right next
to each other, not more than a car or two car lengths apart,
traveling at a slow rate of speed.” The cars repeatedly braked
16536              UNITED STATES v. BERBER-TINOCO
and then continued at their slow speed until they were out of
Officer Engelhorn’s view. Officer Engelhorn did not stop the
vehicles at that point; he wanted to see if the two vehicles
continued westbound in the same direction toward Honey
Springs, which would suggest the vehicles were merely local
traffic.

   After the vehicles left his sight, Officer Engelhorn pulled
out and followed the vehicles westbound toward the juvenile
detention center. Given the terrain and the officer’s attempt to
remain undetected, he did not have the cars within his vision
the entire time. He then saw the two cars turn around at the
detention center and return eastbound. The Durango passed
him, and the pickup truck pulled over between a 15-mile
marker and the detention center. It then pulled out again and
continued east.

   According to Officer Engelhorn, the area where the vehi-
cles were turning around was heavily used for loading aliens.
He testified that “based on [his] experience, it’s almost a
nightly occurrence between there and the 15-mile marker and
the . . . fire station.” Given the alarm from the seismic intru-
sion device, the timing when the vehicles approached the
area, and their conduct which included turning around at
known loading spots, the officer believed the vehicles were
loading up with illegal aliens as part of a smuggling opera-
tion. Relying on this evidence and their suspicions, the offi-
cers made an investigatory stop of the two vehicles at that
point.

  Berber, a passenger in one of the vehicles, was arrested and
charged with unlawful re-entry into the United States after
deportation in violation of 8 U.S.C. § 1326.1 Berber filed a
  1
   8 U.S.C. § 1326(a) provides:
      Subject to subsection (b) of this section, any alien who—
        (1) has been denied admission, excluded, deported, or removed
      or has departed the United States while an order of exclusion,
      deportation, or removal is outstanding, and thereafter
                 UNITED STATES v. BERBER-TINOCO                     16537
motion to suppress evidence of his fingerprints and statements
to the officers as the fruits of an allegedly unlawful stop. After
an evidentiary hearing, the district court denied the motion to
suppress. Berber entered into a conditional guilty plea agree-
ment that allowed him to appeal this ruling.

                                   II

  We review de novo whether the officers had reasonable
suspicion to make an investigatory stop. Ornelas v. United
States, 

, 699 (1996). We review the district
court’s findings of fact for clear error. Id.; United States v.
Tiong, 

, 1139 (9th Cir. 2000).

   [1] The Fourth Amendment right to be secure from unrea-
sonable searches and seizures by the government “applies to
all seizures of the person, including seizures that involve only
a brief detention short of traditional arrest.” United States v.
Brignoni-Ponce, 

, 878 (1975). A brief investiga-
tory stop does not violate the Fourth Amendment, however,
“if the officer has a reasonable suspicion supported by articul-
able facts that criminal activity ‘may be afoot.’ ” United
States v. Sokolow, 

, 7 (1989).

  In determining whether a stop was justified by a reasonable
suspicion, we consider whether, in light of the totality of the

      (2) enters, attempts to enter, or is at any time found in, the
   United States, unless (A) prior to his reembarkation at a place
   outside the United States or his application for admission from
   foreign contiguous territory, the Attorney General has expressly
   consented to such alien’s reapplying for admission; or (B) with
   respect to an alien previously denied admission and removed,
   unless such alien shall establish that he was not required to obtain
   such advance consent under this chapter or any prior Act,
   shall be fined under Title 18, or imprisoned not more than 2
   years, or both.
16538           UNITED STATES v. BERBER-TINOCO
circumstances, the officer had “a particularized and objective
basis for suspecting the particular person stopped of criminal
activity.” United States v. Cortez, 

, 417-18
(1981). For purposes of this analysis, the totality of the cir-
cumstances includes “objective observations, information
from police reports, if such are available, and consideration of
the modes or patterns of operation of certain kinds of law-
breakers.” 

In the context of border patrol stops, the
totality of the circumstances may include “(1) characteristics
of the area; (2) proximity to the border; (3) usual patterns of
traffic and time of day; (4) previous alien or drug smuggling
in the area; (5) behavior of the driver, including ‘obvious
attempts to evade officers’; (6) appearance or behavior of pas-
sengers; (7) model and appearance of the vehicle; and, (8)
officer experience.” United States v. Garcia-Barron, 

, 1307 (9th Cir. 1997) (quoting 

).

   As noted above, in order to uphold the validity of the inves-
tigatory stop, we must discern from this melange of factors “a
particularized and objective basis for suspecting the particular
person stopped of criminal activity.” 

-
18. Often, the data in the record seems equally capable of sup-
porting an innocent explanation as a reasonable suspicion. In
such cases, the Supreme Court directs us to give due weight
to the factual inferences drawn by law enforcement officers,
United States v. Arvizu, 

, 277 (2002), and has
noted that officers may make reasonable deductions and infer-
ences based on their experience and specialized training that
“might well elude an untrained person.” 

(internal
quotation marks omitted). In this vein, the Court has empha-
sized that even when factors considered in isolation from each
other are susceptible to an innocent explanation, they may
collectively amount to a reasonable suspicion. 

Of
course, officers cannot rely solely on factors that would apply
to many law-abiding citizens. See, e.g., United States v. Diaz-
Juarez, 

, 1141 (9th Cir. 2002) (“Reasonable
suspicion may not be based on broad profiles which cast sus-
               UNITED STATES v. BERBER-TINOCO            16539
picion on entire categories of people without any individual-
ized suspicion of the particular person to be stopped.”)
(internal quotation marks omitted); United States v. Sigmond-
Ballesteros, 

, 1127 (9th Cir. 2002) (holding that
there was no reasonable suspicion where the factors underly-
ing the suspicion depicted “ ‘a very large category of presum-
ably innocent travelers, who would be subject to virtually
random seizures were the Court to conclude that as little foun-
dation as there was in this case could justify a seizure’ ”)
(quoting Reid v. Georgia, 

, 441 (1980)). How-
ever, the Supreme Court prohibits courts from adopting a
“divide-and-conquer analysis” by looking at each factor in
isolation and according it no weight if it is susceptible to an
innocent explanation. 

.

   [2] A reasonable suspicion of criminal activity may be suf-
ficiently particularized where officers have narrowed the time
and place of expected criminal activity through deduction or
through a reliable tip. See, e.g., United States v. Paopao, 

, 766-67 (9th Cir. 2006) (holding there was reason-
able suspicion for a protective sweep based on a reasonably
detailed tip from a reliable informant); see also 

. In Cortez, border patrol agents deduced solely
from their observation of footprints in the desert that groups
of aliens, probably led by a guide, were crossing the border
and proceeding 30 miles to an isolated point on Highway 86.
Based on their experience, the officers further deduced that
another crossing was likely to occur on the next clear night,
and that a group would likely arrive at the highway between
2 a.m. and 6 a.m. In light of these “permissible deductions,”

the Supreme Court concluded that the officers had
a reasonable suspicion to stop a pickup truck with a camper
shell (the sort of vehicle the officers expected would be used
to carry aliens that night) that passed a crossing point twice.

421-22; see also United States v. Ordaz, 

(9th Cir. 1998) (holding that the fact that the offi-
cers knew that border sensors had been activated, and one
officer had seen a bundle put in a vehicle of undetermined
16540           UNITED STATES v. BERBER-TINOCO
make, was a sufficient basis for reasonable suspicion to stop
four vehicles coming out of the observed area).

   [3] In this case, based on the totality of the circumstances,
we conclude that the officers did have an objective and partic-
ularized suspicion that the two vehicles observed on Lyons
Valley Road were “engaged in wrongdoing.” 

. First, the officers were able to narrow their suspicion
through deduction. The officers testified that a seismic intru-
sion device was activated, which in their experience indicated
that someone had just illegally crossed the border. We have
long accepted alarms from seismic intrusion devices at the
border as an acceptable factor in a reasonable suspicion analy-
sis. See, e.g., United States v. Olafson, 

, 439-40
(9th Cir. 2000); United States v. Avalos-Ochoa, 

, 1301-02 (9th Cir. 1977). The officers deduced that ille-
gal aliens would likely be picked up at the Lyons Valley Road
loading area that was notorious for alien smuggling. Because
the site was within a two hour walk from the border, the offi-
cers reasonably deduced that vehicles picking up aliens were
likely to arrive at the site during that time frame, and therefore
staked out the site at that time to watch for suspicious behav-
ior. The ensuing conduct of the vehicles, which arrived at the
suspected time at the suspected site, created a particularized
set of circumstances and did not raise a concern that officers
might on this basis target “[t]housands of United States citi-
zens.” United States v. Salinas, 

, 395 (9th Cir.
1991). Indeed, the chain of deductions here was much more
direct than the reasoning upheld by the Supreme Court in
Cortez.

   [4] Second, the officers made reasonable factual inferences
based on their experience with smuggling activities in the
area. The officers testified that at that hour (about 10:30 at
night) in that rural, remote area, local traffic would normally
travel around 55 miles per hour and continue westbound
toward Honey Springs. Therefore, it was reasonable for the
officers to conclude that the behavior of the two vehicles at
                   UNITED STATES v. BERBER-TINOCO                    16541
issue was suspicious, given that the vehicles arrived at the site
traveling slowly, closely together, braking periodically, stop-
ping at known pick-up areas, and finally turning around and
reversing direction to travel eastbound.

   [5] In light of the totality of the circumstances, giving due
weight to the officers’ experience and reasonable deductions,
we conclude that the officers had a reasonable, particularized
basis for suspecting the vehicles of picking up illegal aliens,
and that their stop was supported by reasonable suspicion.
Accordingly, we reject Berber’s arguments that the grounds
for the officers’ suspicions lacked particularity and that each
of the factors, taken individually, is susceptible of innocent
explanation. See 

. Alternate expla-
nations for individual factors are unpersuasive if the factors,
“when viewed in their totality . . . create reasonable suspicion
of criminal activity.” 

.

                                    III

   [6] Berber argues that even if we determine that the investi-
gatory stop was based on reasonable suspicion, we must
reverse the district court for violating Rule 605 of the Federal
Rules of Evidence when the judge made interjections based
on his own knowledge during the suppression hearing.2 Rule
605 provides that “[t]he judge presiding at the trial may not
testify in that trial as a witness.”

  Berber claims that a number of the judge’s interjections
violated Rule 605. First, the judge interrupted defense coun-
  2
    Berber stated that the judge violated 28 U.S.C. § 455(b)(1) by failing
to disqualify himself on the ground that he had “personal knowledge of
disputed evidentiary facts concerning the proceeding.” 28 U.S.C.
§ 455(b)(1). However, Berber has failed to develop this argument, and it
may be deemed abandoned. See Fed. R. App. P. 28(a)(9)(A); United States
v. Kimble, 

, 715 n.2 (9th Cir. 1997). Moreover, the argument
is meritless, because none of the judge’s interjections related to evidenti-
ary facts that were disputed by the parties.
16542           UNITED STATES v. BERBER-TINOCO
sel’s questions to Officer Engelhorn regarding the stop signs
on Lyons Valley Road, and the following exchange took
place:

    Court: Counsel, let me interrupt you for just a sec-
    ond. I’m really familiar with that area. So if you’re
    doing this for my benefit, you can stop because I
    happen to know where that stop sign is and what’s
    further on down at Lyons Valley.

    Defense counsel: This is also for my edification,
    Your Honor.

    Court: This is discovery. This is not a discovery
    motion.

    Defense counsel: I understand, Your Honor; how-
    ever, it is important to my argument. I would like to
    find out from the officer.

    Court: The problem is you’re unduly consuming
    time. The next stop sign beyond that is at Lawson
    Valley Road, which is a long ways down the road,
    so why don’t you move on.

   In subsequent cross-examination, defense counsel again
asked Officer Lenoir about the stop signs on Lyons Valley
Road. The officer testified that there were two stop signs, but
the judge interjected, “Actually, I think there’s four, counsel.”
The judge went on at some length:

    Court: Well, there’s four. Including the whole dis-
    tance of Lyons Valley Road, there’s four. The area
    he’s talking about there’s one at the intersection of
    Lyons and Japatul, and there’s one at Four Corners,
    which is the intersection of Honey Springs, Lyons
    Valley, and Skyline Truck Trail, and it’s a distance
    of about seven miles between those two stretches.
               UNITED STATES v. BERBER-TINOCO            16543
    If that’s what you’re talking about, which I think is
    what the officer’s talking about, for my purposes, for
    the purposes of the hearing today, it doesn’t do any
    good to talk about the second stop sign, or the third
    stop sign at Lawson Valley road, or the fourth stop
    sign, which is down by Skyline Truck Trail, again,
    down at the—almost the intersection of 94.

    Defense Counsel: But there is at least one stop sign
    in this area.

    Court: There’s a stop sign up at Four Corners, and
    there’s a stop sign at Japatul Valley Road and Lyons
    Valley Road. So if you look at it as a piece of string,
    at both ends of that string there are stop signs, okay.

Later, in summing up the evidence, the district court stated:

    First of all, that’s an extremely rural and somewhat
    mountainous area. There’s really not much between
    there and Highway 94 that’s right to the border of
    Mexico, other than the mountains, so to speak.
    That’s a fairly narrow road running from Japatul
    Valley Road to the intersection with Honey Springs,
    not a whole lot of traffic on that road at 10:30 at
    night.

    The evidence before me shows the following: there
    were two vehicles traveling together in a very rural,
    remote area of the county, known to be notorious for
    alien smuggling. They’re traveling slowly. They
    brake periodically. They stop. They keep going.
    They turn around. One of the vehicles again stops.
    And at that point in time the officer, who has had a
    report of a seismic intrusion device, as I said, that
    whole area is—I guess it’s south of Lyons Valley
    Road—is very mountainous, so it makes sense that
    what these officers are waiting for is for someone to
16544           UNITED STATES v. BERBER-TINOCO
    come out of that area, after having triggered the
    motion—the seismic device, and so all this is consis-
    tent with someone who is driving around looking to
    pick up someone.

    I guess one could make the argument, if it was one
    vehicle, perhaps, there wouldn’t be probable cause
    or reasonable suspicion to pull these vehicles over.
    If there were two vehicles, and they were going in
    one direction, and they were traveling at the rate of
    speed—

    By the way, I think, [Defense Counsel], I may be
    mistaken on this, but I think the speed limit in Cali-
    fornia, unless otherwise posted, is 55 miles an hour.
    So if the vehicle is traveling between 20 and 35
    miles an hour, which is a very low rate of speed in
    a rural area, stopping periodically along areas where
    the officers know that people are going to be picked
    up, and particularly following setting off a seismic
    device, I believe that that’s enough to create reason-
    able suspicion.

    I don’t think that the law requires that the officers
    actually see someone load into the vehicles. In fact,
    in that type of area, I suspect that it’s probably very
    difficult to see that sort of thing, which is—that’s
    why they use that area.

   Berber claims that the judge relied on personal knowledge
in commenting on the location of the stop signs and in making
the following six statements: (1) the area at issue is an “ex-
tremely” rural area; (2) “there’s not much between there and
Highway 94 that’s right to the border of Mexico”; (3) “that’s
a fairly narrow road running from Japatul Valley Road to the
intersection with Honey Springs”; (4) there is “not a whole lot
of traffic on that road at 10:30 at night”; (5) “I may be mis-
taken on this, but I think the speed limit in California, unless
                 UNITED STATES v. BERBER-TINOCO                16545
otherwise posted, is 55 miles an hour. So if the vehicle is trav-
eling between 20 and 35 miles an hour, which is a very low
rate of speed in a rural area . . . .”; and (6) “in fact, in that type
of area, I suspect that it’s probably very difficult to see that
sort of thing [loading of aliens], which—that’s why they use
that area.” Berber claims these interjections violated Rule
605.

   [7] We agree that the judge violated Rule 605 when he
interjected his own observations regarding the location of the
stop signs along the Lyons Valley Road and the narrowness
of the road from Japatul Valley Road to the intersection with
Honey Springs. At the time the judge first stated these facts,
they were not in the record nor were they reasonable infer-
ences from the record. Although a closer call, the judge also
violated Rule 605 when he relied on personal knowledge to
conclude that no speed limit was posted on Lyons Valley
Road and therefore the speed limit was 55 miles per hour.
Although a court might be able to take judicial notice of a
speed limit under some circumstances, see FED. R. EVID.
201(b); United States v. Bradford, 

, 1221 n.8
(7th Cir. 1996), the judge here provided a personal conjecture,
rather than a judicially noticed fact.

   [8] A trial judge is not a competent witness to such factual
issues. See United States v. Lewis, 

, 1385 (9th
Cir. 1987) (citing FED. R. EVID. 605). Nor can the judge take
judicial notice of such issues. “A trial judge is prohibited from
relying on his personal experience to support the taking of
judicial notice. ‘It is therefore plainly accepted that the judge
is not to use from the bench, under the guise of judicial
knowledge, that which he knows only as an individual
observer outside of court.’ ” 

J. WIGMORE, EVI-
DENCE IN TRIALS AT COMMON LAW § 2569, at 723) (J. Chabourn
rev. ed. 1981). The type of specific personal knowledge
offered by the judge is not akin to the general knowledge we
have found acceptable in other contexts. See United States v.
Mariscal, 

, 1131-32) (9th Cir. 2002) (holding
16546           UNITED STATES v. BERBER-TINOCO
that judicial knowledge that a road is heavily traveled is
“nothing like the obvious fact that surgery is painful and can
have dire consequences” or “like common knowledge about
the general shape of snowmen”). While a resident judge’s
background knowledge of an area may “inform the judge’s
assessment of the historical facts,” Ornelas v. United States,

, 700 (1996), the judge may not actually testify
in the proceeding or interject facts (excluding facts for which
proper judicial notice is taken). Therefore, the judge erred in
making his observations about such issues.

   The other statements made by the judge in summing up the
evidence did not violate Rule 605. The assertions that the area
at issue was extremely rural and sparsely populated were sup-
ported by the record, given the officers’ testimony that the
area at issue was a rural, remote area, with few residences and
no businesses other than a fire station and a detention center.
Similarly, the judge’s statement that there would be little traf-
fic on the road at 10:30 at night could be reasonably inferred
from the officers’ testimony that the road was in a remote
area. Finally, the judge’s inference that it was probably diffi-
cult to see the alien loading activity was supported by the offi-
cers’ testimony that they did not have a complete view of the
vehicles. A judge may make reasonable inferences from the
record in summing up the evidence without violating Rule
605. See 

.

   [9] Given our conclusion that three of the judge’s remarks
violated Rule 605, we must next determine whether such vio-
lations are subject to harmless error review and, if so, whether
these errors were harmless. In evaluating other violations of
the Federal Rules of Evidence, we have held that we need not
reverse a district court’s decision so long as we have a “ ‘fair
assurance’ that the verdict was not substantially swayed by
error.” United States v. Seschillie, 

, 1214 (9th
Cir. 2002); see also United States v. Morales, 

,
1040 (9th Cir. 1997) (en banc). This standard is equally appli-
cable to violations of Rule 605. See United States v. Nickl,
                UNITED STATES v. BERBER-TINOCO             16547

, 1293 (10th Cir. 2005) (applying harmless
error review to a Rule 605 violation).

   [10] We reject Berber’s argument that a Rule 605 error
constitutes a structural constitutional error requiring reversal.
The Supreme Court has held that only “a limited class of fun-
damental constitutional errors” are structural errors, and not
subject to harmless error analysis. Neder v. United States, 

, 7 (1999). These structural errors include the complete
denial of counsel, a biased trial judge, racial discrimination in
the selection of a grand jury, denial of self-representation at
trial, denial of a public trial, and a defective reasonable doubt
instruction. 

Berber claims that a judge’s interjections
in violation of Rule 605 destroy the court’s image of impar-
tiality and thus violate a defendant’s constitutional right to an
unbiased trial judge. However, as we recently noted, the
Supreme Court has required recusal due to an appearance of
bias (as opposed to actual bias) only when a judge: (i) has a
“direct, personal, substantial pecuniary interest” in the out-
come; (ii) becomes “embroiled in a running, bitter controver-
sy” with a party; or (iii) participates as “part of the accusatory
process.” Crater v. Galaza, 

, 1131 (9th Cir.
2007) (internal quotation marks omitted). Rule 605 violations
will rarely rise to this level. A judge’s conduct during judicial
proceedings “should not, except in the ‘rarest of circum-
stances’ form the sole basis for recusal under § 455(a).”
United States v. Holland, 

, 1124-25 (9th Cir.
2007) (footnote omitted). See also 

.
We therefore decline to hold that a Rule 605 violation, with-
out more, mandates reversal. Here, there was no evidence of
actual bias, and the judge’s conduct does not fall within the
three circumstances where the Supreme Court has required
recusal.

   Because we conclude that this Rule 605 error does not rise
to the level of a structural constitutional error, we apply the
harmless error standard and consider whether there is a “fair
assurance,” based on an independent review of the record,
16548             UNITED STATES v. BERBER-TINOCO
that the judge’s unsupported remarks did not affect the deci-
sion to deny Berber’s motion to suppress. See 

. We undertook a similar inquiry in both Mariscal
and Lewis. In Mariscal, the district court considered whether
an officer had reasonable suspicion to stop a defendant for
failure to give a turn signal “in the event any other traffic may
be affected by the 

(quoting
Ariz. Rev. Stat. § 28-754(A)). Although the prosecution failed
to introduce any evidence as to whether traffic could be
affected by the defendant’s turn, the district court judge con-
cluded that this factor was met because “ ‘McDowell Road is
a heavily traveled east-west street in the City of Phoenix.’ ”

was insufficient reasonable suspicion for the
stop absent the judge’s observation, we determined that “the
objective facts of record” did not support the determination
that there was reasonable suspicion for the stop. We therefore
reversed the district court’s order denying the motion to sup-
press. 

   [11] Here, by contrast, the judge’s interjections regarding
the stop signs and the statement that the road from Japatul
Valley Road to the intersection with Honey Springs was nar-
row did not fill in any critical evidentiary gaps in this case.
The judge’s conjecture as to the speed limit and subsequent
comparison of the slow speed of the vehicles to a speed limit
of 55 miles an hour was cumulative, given the officers’ testi-
mony that the vehicles were traveling at no more than 30
miles per hour, and that traffic typically travels at 50 miles per
hour. An independent review of the record, striking the erro-
neous judicial comments, supports the district court’s ultimate
ruling that the officers in this case had reasonable suspicion
to stop the vehicle in which Berber was traveling. Moreover,
as in Lewis and Mariscal, there is no serious concern here that
the judge’s comments and personal knowledge influenced any
aspect of the trial or hearing other than the judge’s own determi-
nation.3 The judge did not, for instance, make damaging state-
  3
   Berber claims the judge’s statements regarding the location of the stop
signs “tipped off” the prosecutor to Berber’s theory that the cars were
                   UNITED STATES v. BERBER-TINOCO                    16549
ments to the jury. Cf. United States v. Pritchett, 

,
320 (6th Cir. 1983) (holding that the trial judge’s statements
in front of the jury that one of defendant’s acquaintances was
a convicted cocaine dealer created “a sufficient risk of preju-
dice” requiring reversal).

   [12] It was inappropriate for the judge to interrupt question-
ing in order to interject his personal knowledge of facts out-
side the record. Nevertheless, because we can say with fair
assurance that the district court’s violations of Rule 605 were
harmless, we affirm.

   AFFIRMED




braking on the road because of the stop signs and not to pick up aliens at
loading points. However, the defense counsel’s initiation of a line of ques-
tions about the stop signs was sufficient to “tip off” the prosecutor. Berber
also claims that the judge erroneously curtailed this line of inquiry. Given
the district court’s “wide discretion in limiting the scope of cross-
examination,” the court did not err in cutting short the questions about the
stop signs. United States v. Payne, 

, 1469 (9th Cir. 1991).
Moreover, despite the judge’s interruptions, the defense counsel was able
to elicit testimony from the two officers regarding the location of the stop
signs on Lyons Valley Road.