1The Honorable Cynthia H. Hall, United States Circuit Judge for the Ninth

Circuit, sitting by designation.

United States Court of Appeals

FOR THE EIGHTH CIRCUIT

___________

No. 98-2430

___________

United States of America, *

*

Appellee, *

* Appeal from the United States

v. * District Court for the 

* District of South Dakota.

Anthony George Iron Cloud, Sr., *

*

Appellant. *

___________

Submitted: December 15, 1998

Filed: March 19, 1999

___________

Before MCMILLIAN, LAY and HALL,1 Circuit Judges.

___________

LAY, Circuit Judge.

Anthony George Iron Cloud, Sr. was convicted by a jury of involuntary

manslaughter under 18 U.S.C. §§ 1153 and 1112. He appeals the district court’s
2The exact amount of alcohol that Iron Cloud had consumed is a matter of

dispute. Iron Cloud contends that he had six beers. Based upon the various tests

given to Iron Cloud after the accident, including the PBT, the government contended

that Iron Cloud drank eleven beers during that time period. There was also disputed

evidence that Iron Cloud had been smoking marijuana. This information was

obtained by a blood test taken five hours after the accident. The government’s expert

testified that Iron Cloud smoked marijuana within the time period of one hour before

the crash to when the blood was taken. Iron Cloud contends that he had not smoked

marijuana for two days before the accident. 

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decision to admit into evidence the results of a portable breath test (“PBT”) claiming

that its admission deprived him of a fair trial. We reverse and remand for a new trial.

I. FACTS

At 9:30 p.m. on January 19, 1997, Anthony Iron Cloud gave a friend a ride to

his home in the Evergreen housing area of Pine Ridge Reservation. According to

Iron Cloud, he had consumed six beers over the course of six hours.2 When Iron

Cloud reached the housing area, he saw a pedestrian, Abel Iron Rope, walking along

the right-hand side of the road. According to Iron Cloud, he pulled over to the left

to avoid the pedestrian. He then turned to look at his passenger and hit Iron Rope.

It is undisputed that Iron Cloud never applied his brakes and was driving 15 miles per

hour in a 10 mile per hour zone before the accident occurred. 

Abel Iron Rope had an extensive history of mental illness and was

characterized by his family as a danger to himself and to the community. Iron Rope

also had a history of jumping in front of cars. In 1993, he jumped in front of a

propane truck on the highway causing the truck to careen into a ditch. Furthermore,

a police officer testified that at approximately 4:00 p.m. on January 19, 1997, the day

of the accident, Iron Rope ran out directly in front of his patrol car and the officer was

barely able to avoid hitting him.
3

Iron Cloud claims that he left the scene because he was afraid of being

attacked by bystanders and went straight home to call 911. 

4Without using the PBT evidence, Iron Cloud’s expert testified that his bloodalcohol level would have been .07 to .09 percent. The government contends that even

without the PBT his blood-alcohol level would still be over .10 percent.

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After the accident, Iron Cloud and his friend checked on Iron Rope, who was

sitting up and nodded when asked if he was fine. Iron Cloud left the scene of the

accident, went home, and asked his wife to call 911.3 The police arrived shortly

thereafter. Twenty-five minutes after the accident, Tribal Officer Twiss administered

a portable breath test (“PBT”) which indicated a blood-alcohol level of .14 percent.

Iron Cloud was arrested and approximately one hour after the accident he was given

an intoxilyzer breath test which registered his blood-alcohol level as .11 percent.

Five hours after the crash, a blood test was taken and registered .033 percent. Abel

Iron Rope subsequently died as a result of the accident.

Iron Cloud was charged with involuntary manslaughter under 18 U.S.C. §§

1153 and 1112 for operating his motor vehicle in a grossly negligent manner. Iron

Cloud filed a motion in limine to exclude the PBT as evidence of anything more than

a screening test used to determine probable cause for arrest. The district court

overruled the motion without an evidentiary hearing. At trial, the government’s

witness was allowed to calculate a blood-alcohol level reading based on a

hypothetical question which included the PBT and the other tests performed on Iron

Cloud. The expert concluded that Iron Cloud’s blood-alcohol level at the time of the

accident was .13 or .14 percent.4 At the conclusion of the trial, the district court gave

a limiting jury instruction which provided that the PBT should not be considered in

isolation, but could be considered with the other tests as proof of intoxication. The

jury found Iron Cloud guilty and he was sentenced to 21 months imprisonment and

three years supervised release. Iron Cloud appeals the admission of the PBT as

substantive proof of his intoxication.
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II. DISCUSSION

Admissibility of the PBT

In United States v. Black Cloud, 101 F.3d 1258 (8th Cir. 1996), this court set

forth a two part test to determine when scientific testimony is admissible. First, the

district court must “determine whether the testimony is based on reliable scientific

technique, and whether it will assist the jury.” Black Cloud, 101 F.3d at 1261

(citation omitted). In its determination, the district court should consider the

following factors when assessing the reliability of a scientific technique: “(1) whether

the technique can be and has been tested; (2) whether the technique has been

subjected to peer review and publication; (3) the known or potential rate of error for

the technique and the existence and maintenance of standards for controlling the

technique’s operation; and (4) whether the technique is generally accepted in the

scientific community.” Id. (citing Daubert v. Merrell Dow Pharmaceuticals, Inc.,

509 U.S. 579, 593-95 (1993)). Second, even if the district court concludes that the

expert testimony is admissible, it “may exclude the testimony if the testimony has an

unfairly prejudicial effect that substantially outweighs its probative value.” Id.

(citations omitted). 

The district court in this case did not follow either of these steps. The court

refused to hold a Daubert hearing to determine the reliability of the test, stating

before the jury: “[the] PBT test does not require a Daubert hearing. The PBT test is

a test which has been recognized in the scientific community and as such, Daubert

is not appropriate.” Tr. at 43. Neither did the court analyze whether the test would

be unfairly prejudicial. We review a district court’s decision to admit evidence for

an abuse of discretion. Black Cloud, 101 F.3d at 1261. 
5

See also Boyd v. City of Montgomery, 472 So.2d 694, 697 (Ala. Crim. App.

1985) (holding that preliminary breath tests are only admissible to establish probable

cause); Patrick v. State, 750 S.W.2d 391, 394 (Ark. 1988) (stating that PBT’s are

admissible only on behalf of the defendant because they are unreliable); Attix v.

Voshell, 579 A.2d 1125, 1129 (Del. Super. Ct. 1989) (holding that the PBT can be

admitted only for probable cause and not for substantial evidence because no court

has established that it is reliable); State v. Zell, 491 N.W.2d 196, 197 (Iowa Ct. App.

1992) (stating, “[t]he results of the preliminary screening test are inadmissible

because the test is inherently unreliable and may register an inaccurate percentage of

alcohol present in the breath, and may also be inaccurate as to the presence or absence

of any alcohol at all”); People v. Keskinen, 441 N.W.2d 79, 82 (Mich. Ct. App. 1989)

(holding that court erred in admitting evidence of the defendant’s preliminary breath

test); Justice v. Director of Revenue, 890 S.W.2d 728, 731 (Mo. Ct. App. 1995)

(stating that PBTs are not admissible by statute); State v. Strizich, 952 P.2d 1365,

1371 (Mont. 1997) (holding that the PBT is intended only for determining probable

cause); State v. Klingelhoefer, 382 N.W.2d 366, 369-70 (Neb. 1986) (holding that

preliminary test is only relevant for limited purpose of establishing probable cause);

City of Fargo v. Ruether, 490 N.W.2d 481, 482-83 (N.D. 1992) (holding that an

alcohol screening test cannot be admitted if a defendant admits probable cause);

Commonwealth v. Stanley, 629 A.2d 940, 942 (Pa. Super. Ct. 1993) (stating that PBT

results are inadmissible); Jones v. Town of Marion, 1999 WL 7682, 2 (Va. Ct. App.

1999) (citing to state statute which provides that preliminary breath tests are only to

be used in determining probable cause); Thompson v. State Dept. of Licensing, 960

P.2d 475, 477 (Wash. Ct. App. 1998) (holding that “the results of a portable breath

test are not admissible as evidence at trial or to establish probable cause for arrest”);

State v. Beaver, 512 N.W.2d 254, 358-59 (Wis. Ct. App. 1994) (PBT not admitted).

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By denying Iron Cloud’s request for a Daubert hearing on the reliability of the

PBT, the judge took the accuracy of the PBTs for granted and he ignored established

procedure. Contrary to the court’s statements concerning the reliability of the PBT,

the PBT has not been established as reliable. PBTs are used in the field for screening

purposes. The government’s expert witness, Roger Mathison, agreed that the PBT

was only a preliminary screening test. Tr. at 197-199. Furthermore, almost every

state that has addressed the issue has refused to admit the results of the test for

purposes other than probable cause.5 Although the admissibility of evidence is
Compare State v. Huettl, 379 N.W.2d 298, 305 (S.D. 1985) (holding that PBT results

were inadmissible because of state implied consent statues); State v. Anderson, 359

N.W.2d 887 (S.D. 1984) (holding that because the PBT is a field sobriety test for

establishing probable cause, the results are not admissible against a defendant.).

6United States v. McMillan, 820 F.2d 251, 255 (8th Cir. 1987).

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governed by federal standards,6 in the face of this overwhelming case law as to the

limited reliability of the PBT, we conclude, without further foundation being laid, that

the PBT is not reliable as anything more than a screening test to be used for probable

cause.

We are not persuaded by the government’s argument that the district court was

correct in admitting the results of the PBT test without a Daubert hearing because the

technology has been in use for an extended period of time. The mere fact that a test

has been used for a long time does not make it reliable. The same argument could be

made for polygraph tests, which clearly are not admissible in this circuit. See United

States v. Williams, 95 F.3d 723 (8th Cir. 1996); Connor v. Auger, 595 F.2d 407 (8th

Cir. 1979).

Finally, we hold the error was not cured by the judge’s limiting jury instruction.

Jury Instruction No. 12 stated as follows: 

The Court has permitted the introduction of evidence of a portable

breath test (PBT) taken of the defendant. You are instructed that a PBT

test is not recognized, standing alone, as proof of intoxication. It may

be considered, however, together with the tests of the blood, breath

(intoxilyzer) and other evidence pointing to the question of whether the

defendant was under the influence of alcohol at the time of the event for

which the defendant stands charged.

As we have discussed, the PBT should not be used for anything other than probable

cause determinations. This instruction simply makes matters worse by instructing the
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jury that they can consider the PBT as substantive evidence, albeit in conjunction

with other evidence.

Harmless Error

This court has held that “[e]videntiary rule violations ‘which do not affect [a

defendant’s] constitutional rights are subject to Fed. R. Crim. P. 52(a) harmless error

analysis.’” United States v. DeAngelo, 13 F.3d 1228, 1233 (8th Cir. 1994). Under

this court’s interpretation of Fed. R. Crim. P. 52(a), “[a]n error is harmless if the

reviewing court, after reviewing the entire record, determines that no substantial

rights of the defendant were affected, and that the error did not influence or had only

a very slight influence on the verdict.” United States v. Wilcox, 50 F.3d 600, 603 (8th

Cir. 1995) (citation omitted). We will reverse the conviction “only if the jury may

have been substantially swayed by improperly-admitted evidence. . . .” Id. (citations

omitted).

Iron Cloud was accused of involuntary manslaughter under 18 U.S.C. § 1153

and 1112. The indictment was based upon the allegation that Iron Cloud operated his

motor vehicle in a “grossly negligent manner” with actual knowledge that his conduct

was a threat to the lives of others or with actual knowledge that would reasonably

enable him to foresee the danger to others. The government sought to prove this

allegation primarily by showing that Iron Cloud was intoxicated, and heavily relied

on the PBT results to do so. We find that the jury may have been improperly

influenced by this admitted evidence.

The admission of the PBT results becomes significant considering the

government’s primary contentions. The government used the PBT results in two

ways. First, the government used the results to establish that Iron Cloud was

intoxicated. Without the PBT results, Iron Cloud might have successfully disputed

the level of his intoxication. The PBT was taken only 25 minutes after the accident
7There was a disagreement between the experts as to the proper rate of

elimination to be used in this case. The experts agree that the average person’s rate

is .015. Dr. Looyenga stated that the vast majority of people have rates of elimination

between .01 and .02, and it is just as accurate to use the lower rate as it is to use the

upper rate in computing a blood-alcohol level. The government’s expert, Mr.

Mathison, however, used the elimination rate of .019 to arrive at a blood-alcohol level

of .13 at the time of the accident. This rate of elimination was determined using the

results from the intoxilyzer and the blood test taken five hours after the accident. On

cross-examination, Mr. Mathison admitted that if the elimination rate was determined

using the PBT and the intoxilyzer, it would be .06, which is an unrealistic rate. 

8Dr. Mathison testified: 

Q. Okay. Again, because of the variance, because you are not actually

taking blood and measuring it, now you’ve got another variance in there.

You are trying to transfer information taken from a breath test into a

blood content and you have to apply an arbitrary ratio, arbitrary only in

the sense that it varies individual to individual?

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and registered a blood-alcohol level of .14 percent, well over the legal limit. Without

that level, as the defense expert testified, based on the blood-alcohol reading of Iron

Cloud taken some five hours after the accident, Iron Cloud’s blood-alcohol level at

the time of the accident could have been argued to be between .7 and .8 percent,

which is under the legal limit. In giving this opinion, Dr. Robert Looyenga, a chemist

who was employed for twenty-five years at South Dakota School of Mines &

Technology, assumed the rate of elimination was somewhere between .011 and.015.7

The experts disagreed on the reliability of the intoxilyzer test. The defense

counsel challenged the accuracy of both the PBT and the intoxilyzer tests. The

intoxilyzer test is measured from the use of the breath, not the blood, so a ratio must

be applied to get the results in the form of the blood-alcohol level. The defense

contended that this ratio can lead to inaccuracies. The government’s expert conceded

on cross-examination that the blood test was the most reliable of the three tests and

that the intoxilyzer test brought many variables into play.8 Of course, the government
A. Yes, that’s correct.

Q. There can be, again, a range of inaccuracy up to 10 percent on that,

isn’t that right?

A. That’s correct.

Q. In addition to that, if the machine is not calibrated properly and

regularly, then the intoxilyzer test can be off because of erroneous

calibration?

A. Certainly is possible with the use of the intoxilyzer the calibration

is checked before and after the actual breath test is –

Tr. at 202-03.

9As we pointed out in McMillan, the variables associated with the intoxilyzer

breath test go to the weight and not the admissibility of the tests. McMillan, 820 F.3d

at 255. 

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disputed the challenges to the intoxilyzer’s accuracy.9 It was obviously for the jury

to determine the credibility of the conflicting opinions of the two experts. Our

primary concern, however, is whether the admission of the PBT test, which showed

that Iron Cloud had a much higher alcohol content, bolstered the reliability of the

intoxilyzer test and, therefore, influenced the jury in accepting the testimony of the

government expert over the testimony of the defense. We cannot be sure that the PBT

did not substantially sway the jury in this manner.

The admission of the PBT to prove intoxication is also important considering

the circumstances surrounding the accident. It is undisputed that Abel Iron Rope had

mental instabilities and had run out in front of cars on at least two previous occasions.

In fact, he ran in front of a police officer’s car earlier in the afternoon on the day of

the accident in question and was nearly hit. Without the PBT to support the theory
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that Iron Cloud was intoxicated, it is possible the jury could have found that the

accident occurred because Abel Iron Rope ran in front of Iron Cloud’s car. 

Second, the government used the PBT results to undermine the veracity of the

defendant. Iron Cloud testified that he drank only six beers that day. According to

the government’s expert’s testimony, however, Iron Cloud would have had to

consume at least eleven beers within that time period to have a blood-alcohol level

of .13 or .14, the level derived by considering the PBT. Without the PBT results, Iron

Cloud’s blood-alcohol level could have been as low as .07 or .08 at the time of the

accident. As a result, Iron Cloud’s testimony would have been consistent with the

evidence of the lower blood-alcohol level and his credibility would not have been so

easily challenged. 

We cannot say that the jury was not greatly influenced by the high bloodalcohol level registered through the PBT shortly after the accident, either as proof of

the defendant’s intoxication or of his lack of credibility. Therefore, admitting the

PBT results was not harmless error. 

III. CONCLUSION

For the foregoing reasons, the judgment of the district court is reversed and the

case is remanded to the district court for a new trial.

HALL, Circuit Judge, concurring in part and dissenting.

I agree with the majority that the district court erred by admitting into evidence

the PBT results. However, because I believe that the admission of the PBT results

had only a slight influence on the jury’s verdict, I believe that the district court’s error

was harmless. Therefore, I dissent.
10The Supreme Court has determined that the intoxilyzer test is an accurate and

reliable method of measuring blood-alcohol concentration. See California v.

Trombetta, 467 U.S. 479, 489 (1984).

11The Supreme Court stated that the gas chromatography test is highly accurate

in identifying the presence of alcohol and drugs in a subject’s blood. Skinner v.

Railway Labor Executives’ Ass’n, 489 U.S. 602, 610 n.3 (1989).

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“This circuit has established that conviction of involuntary manslaughter

requires proof that a defendant acted grossly negligent in that he acted with a wanton

or reckless disregard for human life, knowing that his conduct was a threat to the lives

of others or having knowledge of such circumstances as could enable him to foresee

the peril to which his act might subject others.” United States v. F.D.L., 836 F.2d

1113, 1118 (8th Cir. 1988). The evidence presented at trial showed that Iron Cloud

was under the influence of alcohol and marijuana while speeding at night through a

residential neighborhood on the wrong side of the road and that, immediately after

seeing Able Iron Rope walking along the side of the road, Iron Cloud took his eyes

off the road to carry on a conversation with his passenger and ran over Iron Rope. 

Independent of the PBT results, the government introduced the results of an

intoxilyzer test,10 administered less than one hour after the accident, indicating that

Iron Cloud’s blood-alcohol content was 0.11. In addition, the government introduced

the results of a gas chromatography test11 that, when taken together with the results

of the intoxilyzer test, indicated that Iron Cloud’s blood alcohol content at the time

of the accident was 0.13. Even Iron Cloud introduced evidence showing that his

blood alcohol content at the time of the accident was between 0.07 and 0.09. The

government’s expert testified that Iron Cloud’s ability to drive safely would have

been significantly impaired at a blood alcohol concentration of 0.08. In addition to

the evidence of Iron Cloud’s blood alcohol concentration, the government introduced

evidence showing that Iron Cloud had been smoking marijuana shortly before the

accident. The government’s expert testified that the marijuana would have
12The majority suggests that the admission of the PBT results caused the jury

to question Iron Cloud’s credibility with respect to his testimony that he drank only

six beers instead of the 11 or 12 to which the government’s witness testified.

However, I believe that Iron Cloud’s evasive behavior following the accident gave

the jury adequate reason to question Iron Cloud’s testimony.

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aggravated any impairment from which Iron Cloud was suffering due to the alcohol.

Therefore, the jury could have inferred that, even at a blood alcohol content as low

as 0.07, Iron Cloud’s ability to drive safely was more significantly impaired as a

result of the marijuana.

In addition to the empirical evidence of Iron Cloud’s impaired ability to drive,

the government showed that, instead of staying to help Iron Rope, Iron Cloud fled the

scene of the accident and returned home. Although Iron Cloud claims to have told

his wife to call 911, he testified that he did not know whether she ever made that call.

When the police arrived at Iron Cloud’s house, his wife met them at the door and told

them Iron Cloud was asleep. However, when Iron Cloud came out of his bedroom,

the police noticed that he did not look like he had been sleeping, but instead appeared

nervous and intoxicated.12

Under these circumstances, I believe that the evidence shows overwhelmingly

that Iron Cloud knew that his actions were a threat to Iron Rope’s life, and that

despite this knowledge Iron Cloud acted in wanton disregard of Iron Rope’s life.

Based on the overwhelming evidence demonstrating that Iron Cloud was grossly

negligent in running over Iron Rope, I believe that the PBT result had “only a very

slight influence on the verdict,” and that its admission was therefore harmless error.

See United States v. Wilcox, 50 F.3d 600, 603 (8th Cir. 1995) (citation omitted). 

The majority suggests that Iron Cloud should be absolved of guilt because Iron

Rope may have jumped in front of Iron Cloud’s truck. I cannot agree because if Iron

Cloud had not been drinking and smoking marijuana before driving, and had not been
13The two drivers who testified about their encounters with Iron Rope were

both able to avoid hitting him. In addition, I note that, because Iron Cloud was

looking at his passenger instead of the road, and because his passenger was seated to

his right, Iron Cloud was looking in the direction from which Iron Rope allegedly

jumped. However, Iron Cloud never even saw Iron Rope until after he had driven

completely over him. I believe that Iron Cloud’s wanton inattention to the road,

knowing that he was in a residential neighborhood and knowing that a pedestrian was

walking on the side of the road, coupled with the darkness of night, the excessive

speed at which he was driving, and the drug-induced impairment of his ability to

drive constitutes gross negligence.

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speeding and ignoring the road while he was driving, he could have avoided Iron

Rope, even if Iron Rope did jump in front of Iron Cloud’s truck.13 Therefore, I

believe that Iron Cloud’s operation of his truck in this manner was grossly negligent,

despite the possibility that Iron Rope jumped in front of Iron Cloud’s truck. 

Based on the foregoing, I believe that the judgment against Iron Cloud should

be affirmed. 

A true copy.

Attest:

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