*Honorable Terry C. Kern, United States District Judge for the Northern District of

Oklahoma, sitting by designation.

PUBLISH

UNITED STATES COURT OF APPEALS

Filed 3/19/96

TENTH CIRCUIT

UNITED STATES OF AMERICA, )

)

Plaintiff-Appellee, )

)

v. ) No. 95-4011

)

LUIS ORREGO-FERNANDEZ, )

)

Defendant-Appellant. )

Appeal from the United States District Court

for the District of Utah

(D.C. No. 93-CR-222)

G. Fred Metos, Salt Lake City, Utah, for Defendant-Appellant.

Bruce C. Lubeck, Assistant United States Attorney (Scott M. Matheson, Jr., United States

Attorney, with him on the brief), Salt Lake City, Utah, for Plaintiff-Appellee.

Before SEYMOUR, Chief Judge, BARRETT, Circuit Judge, and KERN, District

Judge.*

SEYMOUR, Chief Judge.
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Mr. Luis Orrego-Fernandez was convicted of possession of a controlled substance

with intent to distribute in violation of 21 U.S.C. § 841(a)(1) after the district court denied

his motion to suppress the evidence seized as a result of the stop, detention, and search of

the pickup truck he was driving. He contends on appeal the district court erroneously (1)

rejected the credibility findings of the magistrate, (2) found that Trooper Miller observed

alterations to his truck, (3) held lawful the stop and his detention, and (4) found voluntary

his consent to the search of the truck he was driving. We affirm.

I.

Mr. Orrego-Fernandez was driving a 1987 Mazda pickup truck north on Interstate

15 at approximately sixty miles per hour. Utah Highway Patrol Trooper Douglas R.

Miller was traveling south on Interstate 15 at approximately sixty to sixty-five miles per

hour. As the trooper passed Mr. Orrego-Fernandez, he noticed that the truck did not have

a front license plate, was freshly painted, and appeared to have been altered. Trooper

Miller turned his vehicle and followed Mr. Orrego-Fernandez. The trooper noted that the

truck had a rear Pennsylvania license plate but did not know whether Pennsylvania

required a front license plate. He confirmed the truck was altered as he followed and

pulled into the lane next to it. Eventually he turned on his overhead lights and stopped

the truck. 

Trooper Miller further confirmed the truck was altered as he approached the
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driver’s side. When he requested a driver’s license and truck registration, Mr. OrregoFernandez produced a New Jersey driver’s license bearing his name but was unable to

produce a registration. Instead he offered an insurance card which indicated the truck

was registered in Pennsylvania to Mr. Jose Caez. Trooper Miller asked Mr. OrregoFernandez if he had permission to use the truck. Mr. Orrego-Fernandez replied that he

did and stated that Mr. Caez was his cousin. The trooper then informed Mr. OrregoFernandez he had stopped him because of a possible registration violation. Trooper

Miller testified, however, that he actually stopped the truck because he suspected it had a

hidden compartment which probably contained drugs or guns.

Trooper Miller went back to his car to verify Mr. Orrego-Fernandez’s license and

the registration of the truck. The dispatcher stated that no information could be found

with respect to Mr. Orrego-Fernandez’s license but verified that the owner of the truck

was Mr. Caez. The trooper returned to the truck and, while holding Mr. OrregoFernandez’s license and the insurance card, asked if there were any guns or drugs in the

truck. Mr. Orrego-Fernandez responded that there were no guns or drugs. Trooper Miller

then asked if he could search the truck for guns and drugs, to which Mr. OrregoFernandez responded, “sure, if you want to.” Rec., supp. vol. III, at 34. The trooper

requested Mr. Orrego-Fernandez to get out of the truck and stand on the shoulder. In the

meantime, two additional troopers arrived on the scene. Trooper Miller searched the

exterior of the truck for further signs of a hidden compartment and found that the gas tank
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intake hose had been altered and that there was a gap between the end gate and the bed of

the truck. Both modifications indicated to him that the truck contained a hidden

compartment. Trooper Miller testified he then arrested Mr. Orrego-Fernandez because he

thought the alterations to the truck gave him probable cause to believe it contained a

hidden compartment which held guns or drugs. Mr. Orrego-Fernandez and the truck were

transported to the sheriff’s office where Trooper Miller obtained a warrant for a further

search. On further inspection, officers discovered 109 kilogram packages of cocaine in a

hidden compartment.

The district court designated a magistrate judge to conduct a hearing on Mr.

Orrego-Fernandez’s motion to suppress evidence. The magistrate recommended that the

evidence be suppressed. The district court reviewed the magistrate’s findings and the

objections thereto, rejected some of the findings, and denied Mr. Orrego-Fernandez’s

motion to suppress. Mr. Orrego-Fernandez entered a conditional guilty plea and this

appeal followed.

II.

As an initial matter, Mr. Orrego-Fernandez contends the district court erred under

28 U.S.C. §636(b)(1) by rejecting the magistrate’s credibility determination without

rehearing the testimony. Mr. Orrego-Fernandez insists the case should be remanded with

an order requiring the district court either to take testimony or adopt the magistrate’s
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recommendations. 

Under section 636(b)(1)(B), the district court may designate a magistrate judge to

hear certain pretrial motions, including a motion to suppress evidence in a criminal case. 

With respect to such “dispositive” motions, the district court may “designate a magistrate

to conduct hearings, including evidentiary hearings, and to submit to a judge of the court

proposed findings of fact and recommendations for the disposition, by a judge of the

court, of [the] motion.” 28 U.S.C. §636(b)(1)(B). The statute further provides that the

district court 

shall make a de novo determination of those portions of the report or

specified proposed findings or recommendations to which objection

is made. A judge of the court may accept, reject, or modify, in whole

or in part, the findings or recommendations made by the magistrate. 

The judge may also receive further evidence or recommit the matter

to the magistrate with instructions. 

28 U.S.C. §636(b)(1). “‘De novo review is statutorily and constitutionally required . . . .

Where circumstances indicate that the district court has not conducted such review

following timely objection to the magistrate’s report, the case must be remanded for

compliance with the statute.’” Bratcher v. Bray-Doyle Indep. Sch. Dist., 8 F.3d 722, 724

(10th Cir. 1993) (quoting Summers v. Utah, 927 F.2d 1165, 1167 (10th Cir. 1991)). 

However, “the express references to de novo review in [the district court’s] order must be

taken to mean it properly considered the pertinent portions of the record, absent some

clear indication otherwise.” Id. In United States v. Raddatz, 447 U.S. 667, 674 (1980),

the Supreme Court held that section 636(b)(1) requires “a de novo determination, not a de
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novo hearing” where a district court adopts the recommendation of the magistrate. In a

footnote, the Court said “we assume it is unlikely that a district judge would reject a

magistrate’s proposed findings on credibility when those findings are dispositive and

substitute the judge’s own appraisal; to do so without seeing and hearing the witness or

witnesses whose credibility is in question could well give rise to serious questions which

we do not reach.” 447 U.S. at 681 n.7. The Court’s caveat, however, was directed only

to findings that are dispositive.

Thus, before we determine whether the district court is required to rehear

testimony, we must decide whether the magistrate’s credibility findings were dispositive

or material to the district court’s holding. The district court here stated it would make a

de novo determination, and then held that the alterations to the truck observed by Trooper

Miller, given his experience with similar alterations to similar trucks, constituted

reasonable suspicion. The question is whether the magistrate made material, contrary

credibility findings with respect to Trooper Miller’s testimony that he observed the

truck’s alterations.

The magistrate first noted that Trooper Miller testified he made certain

observations as he passed the truck going the opposite direction. The magistrate found

that Trooper Miller could not have made the asserted observations because of the distance

between, and speed of, the respective vehicles. This credibility finding is not material

because Trooper Miller did not base his stop on that observation. The trooper also
1Because the truck was actually altered, the fact that Trooper Miller failed to

document the alterations in his report is not determinative of whether he observed them. 

Similarly, the fact that the altered truck on which Trooper Miller was trained to recognize

a hidden compartment may not have actually contained drugs is not material to whether

Trooper Miller observed similar alterations indicating a hidden compartment in the instant

case.

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testified he confirmed his observations when he followed the truck prior to the stop. The

magistrate did not find otherwise.

We have thoroughly reviewed the record and conclude that the magistrate did not

make material credibility findings contrary to the district court’s conclusion. The

magistrate did not specifically discredit Trooper Miller’s testimony regarding his closer 

observations of the alterations. Nor did the magistrate’s credibility findings address

Trooper Miller’s demeanor or any other factor gleaned from live testimony. Instead, the

magistrate personally observed the truck’s alterations but concluded that they were

consistent with innocent behavior.1

 The district court disagreed and held that the

alterations constituted reasonable suspicion of criminal activity. Whether the alterations

were innocent in nature is not a credibility determination. Because the magistrate’s

credibility findings were not material to the district court’s ultimate determination, we do

not address whether a district court’s rejection of such findings requires rehearing the

testimony.
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III.

We review the factual findings in support of a district court’s denial of a motion to

suppress evidence under the clearly erroneous standard. United States v. Betancur, 24

F.3d 73, 76 (10th Cir. 1994). We consider the evidence in the light most favorable to the

district court’s ruling. United States v. Soto, 988 F.2d 1548, 1551 (10th Cir. 1993). We

review the question of standing and the ultimate determination of reasonableness de novo. 

Betancur, 24 F.3d at 76; Soto, 988 F.2d at 1551.

A.

We turn first to the issue of standing. The district court relied on United States v.

Soto, 988 F.2d 1548, and United States v. Rubio-Rivera, 917 F.2d 1271 (10th Cir. 1990),

to hold that Mr. Orrego-Fernandez had standing to challenge the search of the truck. The

government contends Mr. Orrego-Fernandez lacked standing because he did not produce

a registration.

“The standing inquiry focuses on reasonable expectations, hence, a defendant is

not required ‘to produce legal documentation showing a chain of lawful custody from the

registered owner’ to himself.” Rubio-Rivera, 917 F.2d at 1275 (quoting United States v.

Arango, 912 F.2d 441, 446 n.2 (10th Cir. 1990), cert. denied, 499 U.S. 924 (1991). In

Rubio-Rivera, the “[d]efendant satisfied the requirement that he ‘must at least state that

he gained possession from the owner or someone with the authority to grant possession’”
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when he testified the owner directed him to “papers” in the glove box indicating

ownership. Rubio-Rivera, 917 F.2d at 1275 (quoting Arango, 912 F.2d at 445).

Here, Mr. Orrego-Fernandez introduced evidence that he had a reasonable

expectation of privacy in the vehicle when he stated he received permission from the

owner to use the truck. In addition, he produced a Pennsylvania insurance card which

identified the individual he named as the owner of the truck. Trooper Miller testified the

dispatcher confirmed that the individual on the insurance card was the owner of the truck. 

“Where the defendant offers sufficient evidence indicating that he has permission of the

owner to use the vehicle, the defendant plainly has a reasonable expectation of privacy in

the vehicle. . . .” Rubio-Rivera, 917 F.2d at 1275 (citation omitted). We hold that Mr.

Orrego-Fernandez has standing to challenge the search of the truck.

B.

Mr. Orrego-Fernandez first asserts the district court erred when it found that

Trooper Miller observed alterations to the truck. We are not persuaded. The government

submitted exhibits demonstrating the alterations described by Trooper Miller were

observable. The trooper certainly got close enough to the truck to observe it from behind

and on the side before he stopped it. The district court relied upon the experience and

testimony of Trooper Miller and the exhibits corroborating his testimony to conclude that

he observed the alterations. Under these circumstances, we can not say the district court’s
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finding that Trooper Miller observed the alterations to the truck is clearly erroneous.

C.

Mr. Orrego-Fernandez also asserts the alterations to the truck did not provide

reasonable suspicion of criminal activity to support the stop. The Fourth Amendment

prohibits unreasonable searches and seizures. The stopping of a vehicle constitutes a

“seizure.” United States v. Walker, 933 F.2d 812, 815 (10th Cir. 1991), cert. denied, 502

U.S. 1093 (1992). A vehicle stop is usually a limited seizure, however, “and is more like

an investigative detention than a custodial arrest.” Id. We therefore analyze the stop and

detention of a vehicle under the principles of Terry v. Ohio, 392 U.S. 1 (1968). See

Berkemer v. McCarty, 468 U.S. 420, 439 (1984) (“[T]he usual traffic stop is more

analogous to a so-called ‘Terry stop’ . . . than to a formal arrest.”); Betancur, 24 F.3d at

78 (“A temporary detention [of a vehicle’s driver] for questioning is justified when the

officer has reasonable suspicion ‘of illegal transactions in drugs or of any other serious

crime.’”) (quoting Florida v. Royer, 460 U.S. 491, 499 (1983)). See also Soto, 988 F.2d

at 1554; United States v. Horn, 970 F.2d 728, 731 (10th Cir. 1992); Walker, 933 F.2d at

815. Under Terry, we examine “whether the officer’s action was justified at its inception,

and whether it was reasonably related in scope to the circumstances which justified the

interference in the first place.” 392 U.S. at 20. “[I]n justifying the particular intrusion the

police officer must be able to point to specific and articulable facts which, taken together
2

 Otherwise innocent behavior may sometimes constitute reasonable suspicion

given the totality of the circumstances. See United States v. Lopez-Martinez, 25 F.3d

1481, 1484 (10th Cir. 1994) (“In making a determination of probable cause the relevant

inquiry is not whether particular conduct is ‘innocent’ or ‘guilty,’ but the degree of

suspicion that attaches to particular types of noncriminal acts.”) (quoting Illinois v. Gates,

462 U.S. 213, 244 n.13 (1983)).

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with rational inferences from those facts, reasonably warrant that intrusion.” Id. at 21.

Whether alterations to a vehicle in the absence of other factors can constitute

reasonable suspicion that a crime is being committed is a question of first impression for

us, although we have addressed altered vehicles in cases where other factors are present.2

In Betancur, 24 F.3d at 78, for example, we held that an altered truck plus registration

papers which did not establish the defendant as the owner constituted reasonable

suspicion for detaining the vehicle. The defendant there was stopped for speeding. As

the officer approached the stopped truck, he noticed that it was “high,” that the truck’s

bottom appeared lower than normal, and that the rear wheel well area was bright with

fresh undercoating. When questioned about the ownership of the truck, the defendant

provided unsatisfactory answers. The officer then asked the defendant whether he had

cocaine or marijuana. The defendant subsequently argued the continued detention 

unreasonably exceeded the scope of the reason for the initial stop. We upheld the

temporary detention because the officer reasonably suspected the transportation of

contraband based on evidence of a hidden compartment under the bed of the truck and the

inability of the defendant to prove lawful possession of the truck.
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In United States v. Arango, 912 F.2d at 447, we held that evidence of a hidden

compartment plus an inadequate amount of luggage for a purported two-week vacation

constituted probable cause. The defendant there was stopped for speeding. The officer

gave the defendant a citation for speeding and then asked for and received consent to

search the truck for alcohol, weapons, or drugs. In the meantime, a second officer arrived

at the scene. As the second officer walked up to the truck from behind, he noticed that

the bed of the truck was very shallow. After lifting a mat that covered the bed, he 

observed the bed had been modified. The section seams of the bed appeared as if they had

been put in by hand, bolts on the side of the bed did not match the color of the truck, and

several inches existed between the bed of the truck and its undercarriage. Both officers

tapped on the side of the truck, but neither could feel the taps on the other side. The

officers then requested the defendant to follow them to the sheriff’s office. The

defendant asserted his arrest was illegal. We held the de facto arrest legal on the ground

that the alterations to the truck and the lack of luggage gave the officers probable cause to

believe the defendant was transporting contraband.

Two district courts in our circuit have addressed whether alterations to a vehicle

constitute reasonable suspicion of criminal conduct. In United States v. Toro-Pelaez, 893

F. Supp. 963, 966 (D. Kan. 1995), the court held that a truck with a “homemade” bed

constituted reasonable suspicion. Although the defendant was following another vehicle

too closely, one of the two troopers in the patrol car admitted he was going to stop the
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defendant regardless of any traffic violation. The troopers testified they stopped the

defendant because they suspected the truck had a false compartment under the truck bed. 

They followed the truck and pulled into the left lane to get a closer look. Before stopping

the defendant, the troopers observed a discrepancy of six to eight inches between where

the bed should rest on the frame rails of the truck and the actual height of the bed. The

troopers testified that the clues to a false bed included the visibility of the false floor from

the wheel well or the appearance that a spare tire is too low when mounted under the

truck where it belongs. The troopers said they were absolutely certain the truck contained

a false bed based upon knowledge and expertise regarding hidden compartments in

vehicles. Noting that the defendant did not proffer any legitimate purpose for such a

hidden compartment, the court held that evidence of a false bed constituted reasonable

suspicion.

In United States v. Castillo, 864 F.Supp. 1090, 1096-1097 (D. Utah 1994), the

court held that evidence of a “customized” truck, the smell of air freshener from the

truck’s cab, and the defendant’s nervousness did not establish reasonable suspicion. The

defendants were stopped because the driver’s side window was darkly tinted in likely

violation of state law. As the trooper approached the truck, he noticed there were caps on

the tie down holes and fresh undercoating under the wheel wells. After the driver rolled

down her window, the trooper noticed a strong smell of air freshener. The trooper asked

a number of intrusive questions unrelated to the possible traffic violation. Defendants
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asserted that their continued detention was unreasonable because it exceeded the scope of

the reason for the initial stop. The court held that the evidence, including the customized

truck, did not establish reasonable suspicion that defendants were committing a crime.

In this case, Trooper Miller testified he stopped Mr. Orrego-Fernandez because he

observed alterations to the truck. Four factors led to his initial curiosity: (1) the truck was

freshly painted and had a bright finish, (2) the truck frame was noticeably lower in the

back than the front, (3) the leaf springs on the rear axle were only about five inches from

the pavement and (4) the wheel well was solid black and no air space could be seen. In

addition, Trooper Miller observed what he believed to be a gas tank hanging two to three

inches below the frame of the truck, which increased his suspicion that the truck had been

altered to transport contraband. Trooper Miller testified he had been trained on a similar

truck which had a lowered gas tank and a hidden compartment. The truck in the instant

case had been freshly painted over dents that could have been easily removed, raising the

inference that the truck was painted to conceal the alterations. 

While Mr. Orrego-Fernandez was traveling in the outside or slow lane, Trooper

Miller pulled into the inside lane so he could further observe the truck. He testified he

confirmed that the leaf springs were approximately five inches from the ground. He also

confirmed that the wheel well had been recently undercoated with black paint and that

there was no air space between the frame and bed of the truck. Trooper Miller testified

that an unaltered truck has metal slats that reinforce the bed of the truck and tie into the
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frame of the vehicle. Because he could not view the slats from the wheel well, he

concluded that the bed was sitting on the frame of the truck. It was at this point that

Trooper Miller stopped Mr. Orrego-Fernandez.

Alterations to vehicles do not automatically create reasonable suspicion. The

alterations to the vehicle must be such that a trooper may reasonably believe a crime is

being committed. The trooper must go beyond the inarticulable hunch that all customized

vehicles contain hidden compartments and point to specific factors which justify the

objectively reasonable conclusion that particular alterations indicate a hidden

compartment which may contain contraband. The truck in this case was not merely

“customized.” It contained several alterations which in the trooper’s experience were

consistent with the existence of a hidden compartment. On these facts, we hold that the

sum of the particular alterations observed by Trooper Miller created reasonable suspicion

of drug trafficking and satisfied the requirements of the Fourth Amendment for an

investigative detention. 

D.

Our review does not end here because Trooper Miller requested consent to search

the truck. We review a district court’s finding of voluntary consent under the clearly

erroneous standard. United States v. Soto, 988 F.2d at 1557. “The voluntariness of

consent must be determined from the totality of the circumstances, and the government
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bears the burden of proof on the issue.” Id. In making the determination, we do not

presume that the consent was either voluntary or involuntary. United States v. Price, 925

F.2d 1268, 1271 (10th Cir. 1991). To sustain its burden, “the government must show that

there was no duress or coercion, express or implied, that the consent was unequivocal and

specific, and that it was freely and intelligently given.” Soto, 988 F.2d at 1557 (citing

United States v. Price, 925 F.2d at 1270).

Mr. Orrego-Fernandez asserts that his consent was involuntary for several reasons:

(1) the sequence of questions prior to his consent, (2) he was not free to leave, and (3) he

was not informed that he did not have to consent to the search. We must assess whether

taken as a whole, under the totality of the circumstances, the district court’s finding of

voluntary consent is clearly erroneous. 

Failure to inform a defendant that he was free to leave or that he could refuse

consent are “important factors in our consideration.” United States v. McSwain, 29 F.2d

558, 563 (10th Cir. 1994). In McSwain, the initial stop of the defendant violated the

Fourth Amendment. In assessing the totality of the circumstances, we held that the

consent of the defendant did not purge the taint of his illegal detention. The

circumstances of this case, however, are more analogous to Soto where we recognized 

that any detained individual will feel some degree of compulsion but held that detention

does not automatically render consent involuntary. 988 F.2d at 1557-58. Here, as in

Soto, Mr. Orrego-Fernandez was not subjected to an illegal detention. In addition, the
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district court found the following facts. Mr. Orrego-Fernandez was not physically

harmed, and no other officers were present when he gave his consent. Trooper Miller did

not threaten Mr. Orrego-Fernandez or use a threatening tone. The search was conducted

on the shoulder of a public highway in daylight. Trooper Miller asked only once if he

could search the truck for guns or drugs. Mr. Orrego-Fernandez got out of the truck after

the request to allow Trooper Miller to conduct the search. Mr. Orrego-Fernandez’s 

consent was unequivocal and specific. Under these circumstances, the district court’s

finding that Mr. Orrego-Fernandez’ consent was voluntary is not clearly erroneous. 

Moreover, the search did not exceed the consent given. The standard for

measuring the scope of Mr. Orrego-Fernandez’ s consent is “what . . . the typical

reasonable person [would] have understood by the exchange between the [trooper] and

the suspect.” Florida v. Jimeno, 500 U.S. 248, 251 (1991). “The scope of a search is

generally defined by its expressed object.” Id. Trooper Miller’s search of the vehicle did

not exceed the scope of consent. He informed Mr. Orrego-Fernandez that he wanted to

search for guns and drugs. Mr. Orrego-Fernandez did not place any explicit limitation on

the scope of the search. See id. Trooper Miller’s search consisted of an external

examination and the lifting of the camper shell door to examine the bed of the truck. He

did not search the visible luggage in the truck. He did not search any hidden

compartments in the cab or under the bed of the truck. We hold that the search of the
3

 Mr. Orrego-Fernandez does not challenge the arrest on appeal, so we do not

address whether probable cause existed at this point to make an arrest.

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truck prior to Mr. Orrego-Fernandez’s arrest was within the scope of the consent given.3

We AFFIRM the district court’s denial of Mr. Orrego-Fernandez’s motion to

suppress evidence and the judgment of conviction.