Title: Oregon v. Powell
Citation: N/A
Docket Number: S059620
State: Oregon
Issuer: Oregon Supreme Court
Date: July 19, 2012

Filed:  May 10, 2012 
 
IN THE SUPREME COURT OF THE STATE OF OREGON 
 
STATE OF OREGON 
Respondent on Review, 
v. 
 
JAVIER EUMANA-MORANCHEL, 
Petitioner on Review. 
 
(CC 081053188; CA A142632; SC S059602) 
 
 
En Banc 
 
 
 
On review from the Court of Appeals.* 
 
 
Argued and submitted January 9, 2012. 
 
 
Erik Blumenthal, Deputy Public Defender, Salem, argued the cause and filed the 
brief for petitioner on review.  With him on the brief was Peter Gartlan, Chief Defender, 
Office of Public Defense Services. 
 
 
Matthew J. Lysne, Assistant Attorney General, Salem, argued the cause and filed 
the brief for respondent on review.  With him on the brief were John R. Kroger, Attorney 
General, and Anna M. Joyce, Solicitor General. 
 
 
BALMER, C. J. 
 
 
The decision of the Court of Appeals is affirmed.  The judgment of the circuit 
court is reversed, and the case is remanded to the circuit court for further proceedings.   
 
 
De Muniz, J., filed a dissenting opinion in which Durham and Walters, JJ., joined. 
 
 
*Appeal from Multnomah County Circuit Court,  Lewis B. Lawrence, Judge.  243 
Or App 496, 260 P3d 501 (2011). 
 
 
BALMER, C. J. 
1 
 
 
This case arises out of defendant's motion in limine to exclude the 
2 
testimony of the state's expert witness in his prosecution for driving under the influence 
3 
of intoxicants (DUII).  The issue presented is whether the state can introduce an expert's 
4 
testimony to prove that defendant's blood alcohol content (BAC) was over the legal limit 
5 
of .08 percent when a police officer stopped him for driving erratically, even though 
6 
defendant's BAC was under the legal limit at the time of his breath test, approximately an 
7 
hour and a half later.  At the pretrial hearing on defendant's motion, the trial court 
8 
excluded the expert's testimony interpreting defendant's breath test results to the extent 
9 
that that testimony would explain that defendant's BAC was over .08 percent at the time 
10 
he was driving.  The state filed an interlocutory appeal of that ruling and the Court of 
11 
Appeals reversed, concluding that the expert's testimony was derived from a chemical 
12 
analysis of defendant's breath and was, therefore, admissible.  State v. Eumana-
13 
Moranchel, 243 Or App 496, 260 P3d 501 (2011).  We now affirm the decision of the 
14 
Court of Appeals.   
15 
 
 
The parties stipulated to the following facts for purposes of the hearing on 
16 
defendant's motion in limine.  On September 27, 2008, at 3:08 a.m., a police officer 
17 
stopped defendant on a public road in Multnomah County after the officer observed 
18 
defendant's pickup truck weaving across the center line.  The officer noticed that 
19 
defendant's eyes were glassy and that his movements were slow and lethargic.  Defendant 
20 
told the officer that he had had three beers that evening, but had had no alcohol since 2:00 
21 
a.m., when the bars closed.  A second officer arrived on the scene.  She noted the smell of 
22 
 
2 
alcohol emanating from defendant's truck.  She administered field sobriety tests, which 
1 
defendant failed.  The officer arrested defendant for DUII, advised him of his Miranda 
2 
rights, and transported him to the police station.  At 4:42 a.m., the officer administered a 
3 
breath test that measured defendant's BAC at .064 percent, which was below the legal 
4 
limit of .08 percent.1   
5 
 
 
Defendant was charged by information with "misdemeanor driving while 
6 
under the influence of intoxicants."  The offense of driving under the influence of 
7 
intoxicants is defined in ORS 813.010(1), which provides:   
8 
 
"A person commits the offense of driving while under the influence 
9 
of intoxicants if the person drives a vehicle while the person: 
10 
 
"(a) Has 0.08 percent or more by weight of alcohol in the blood of 
11 
the person as shown by chemical analysis of the breath or blood of the 
12 
person made under ORS 813.100, 813.140 or 813.150; 
13 
 
"(b) Is under the influence of intoxicating liquor, a controlled 
14 
substance or an inhalant; or 
15 
 
"(c) Is under the influence of any combination of intoxicating liquor, 
16 
an inhalant and a controlled substance." 
17 
 
 
The information did not identify a particular paragraph of ORS 813.010 
18 
that the state accused defendant of violating.  The state, thus, was free to establish at trial 
19 
that defendant violated ORS 813.010 either by driving while impaired, under ORS 
20 
813.010(1)(b) or (c), or by driving with a BAC of at least .08 percent, under ORS 
21 
                                              
 
1 
The officer first administered a breath test at approximately 4:30 a.m. that 
measured defendant's BAC at .064 percent.  The parties and the expert have relied on the 
second, 4:42 a.m. breath test result in this case and we do the same in this opinion.   
 
3 
813.010(1)(a).  See State v. King, 316 Or 437, 446, 852 P2d 190 (1993), overruled in part 
1 
on other grounds by Farmers Ins. Co. v. Mowry, 350 Or 686, 697, 261 P3d 1 (2011) 
2 
(ORS 813.010(1)(a), (b), and (c) describe single offense, and jury need not agree on 
3 
which test results (BAC or field sobriety tests or combination) established that the driver 
4 
was under the influence).   
5 
 
 
Before trial, the state indicated that it intended to offer an expert's 
6 
testimony to establish defendant's guilt under ORS 813.010(1)(a) -- to prove that 
7 
defendant drove with a BAC of .08 percent -- notwithstanding that his BAC at the time of 
8 
the test was below that legal limit.  As noted, defendant moved in limine to exclude that 
9 
testimony.   
10 
 
 
At the hearing on the motion in limine, the prosecution proffered the 
11 
testimony of Shane Bessett, an expert in the field of alcohol absorption and dissipation, to 
12 
establish that, although defendant's BAC at the time of his breath test was .064 percent, 
13 
his BAC when he was stopped, one hour and 34 minutes earlier, was between .08 and .10 
14 
percent and, therefore, above the legal limit.  Bessett testified that he had arrived at that 
15 
range by using a method called retrograde extrapolation, which he explained as follows:  
16 
Bessett testified that men and women eliminate alcohol at an average rate of .018 percent 
17 
per hour,2 but that the specific elimination rate for any particular individual varies 
18 
according to his or her tolerance for alcohol.  The least alcohol-tolerant drinker would 
19 
                                              
 
2  
Bessett testified that men and women eliminate alcohol at the same rates.   
 
4 
eliminate alcohol at a rate of .01 percent per hour, while the most tolerant drinker would 
1 
eliminate alcohol at a rate of up to .025 percent per hour.3  For that reason, Bessett 
2 
testified, retrograde extrapolation would produce a range for a driver's BAC at any given 
3 
time, rather than a single, specific number.  Further, Bessett testified, to calculate a 
4 
person's BAC at a given time, he would need to know the time of the test, the time of the 
5 
driver's last consumption of alcohol, and the time that the driver was stopped.     
6 
 
 
Bessett testified that, in this case, based on information in the police 
7 
reports, he assumed that defendant had stopped drinking by 2:00 a.m., that he was 
8 
stopped and arrested at 3:08 a.m., and that the breath test at 4:42 a.m. revealed that his 
9 
BAC was .064 percent.4  Based on those assumptions, Bessett then calculated that 
10 
defendant, having eliminated the alcohol in his blood at a rate of between .01 and .025 
11 
percent per hour for one hour and 34 minutes, likely would have had a BAC of between 
12 
.08 and .10 percent when he was driving.   
13 
 
 
The trial court granted defendant's motion to exclude Bessett's testimony.  
14 
                                              
 
3  
Because those parameters would encompass "virtually everyone," which he 
described as 98 out of 100 people tested, Bessett testified that there was no margin of 
error.   
 
4 
Bessett testified that it was important to know when a subject stopped 
drinking, because 80 percent of alcohol is absorbed into the bloodstream within five to 10 
minutes of consumption, and all alcohol consumed ordinarily is absorbed into the 
bloodstream within 30 to 60 minutes.  In this case, Bessett assumed that, when defendant 
was stopped at 3:08 a.m., one hour and eight minutes after defendant stopped drinking, 
defendant would have been eliminating alcohol, not absorbing it.  Defendant did not 
challenge that assumption.  
 
5 
In reaching that result, the court concluded that it was bound by the Court of Appeals 
1 
opinion in State v. Johnson, 219 Or App 200, 182 P3d 256 (2008), which, in its view, 
2 
prevented the state from convicting a defendant for DUII unless a chemical analysis, 
3 
standing alone, proved the defendant's BAC to be at least .08 percent.5  The trial court 
4 
entered an order excluding 
5 
 
"(1)  Any testimony by State's expert witness referring to BAC 
6 
content if that testimony would permit the jury to convict defendant based 
7 
on his BAC. 
8 
 
"(2) Any testimony by State's expert witness that his BAC at the  
9 
time of the alleged stop was at least .08 percent."  
10 
That ruling effectively prevented the state from establishing defendant's guilt under ORS 
11 
813.010(1)(a).   
12 
 
 
The state appealed that pretrial ruling, and the Court of Appeals reversed, 
13 
concluding that Bessett's testimony concerning retrograde extrapolation was admissible, 
14 
because it "was derived, using scientific principles, from a chemical analysis of 
15 
defendant's breath."  Eumana-Moranchel, 243 Or App at 502. 
16 
 
 
In this court, defendant argues that ORS 813.010 provides three methods 
17 
for the state to prove that a defendant was driving under the influence of intoxicants.  
18 
                                              
 
5 
In Johnson, a breath test revealed that the defendant's BAC was .07 percent 
at the time of the test, approximately an hour after the defendant was stopped.  At the 
defendant's trial in that case, the arresting officer testified that, based on his observations, 
the defendant's BAC was at or above .08 percent at the time he was stopped.  The Court 
of Appeals accepted the state's concession that evidence of observable indicia of 
intoxication is not admissible to prove that a defendant's BAC exceeded the legal limit, 
because it is not based on a chemical test of the defendant's breath or blood.  219 Or App 
at 204-05.   
 
6 
Two of those methods, set out in ORS 813.010(1)(b) and (c), require proof that the 
1 
defendant drove while impaired by alcohol or controlled substances.  The third, set out in 
2 
ORS 813.010(1)(a), does not require proof of impairment.  Rather, that paragraph 
3 
requires only that the state prove that the defendant drove with a BAC of .08 percent or 
4 
more "as shown by chemical analysis of the breath or blood of the person."  (Emphasis 
5 
added.)  Defendant argues that, under the plain words of ORS 813.010(1)(a), only a 
6 
chemical analysis can show a BAC of .08 percent or more.  Retrograde extrapolation is a 
7 
formula, not a chemical analysis, defendant asserts, and, therefore, it cannot be used to 
8 
show a particular BAC.  He contends that only the numerical result of the 
9 
chemical<fjanalysis (the breath test result) is admissible to show that he drove a vehicle 
10 
while he had .08 percent or more by weight of alcohol in his blood.  According to 
11 
defendant, any other evidence is irrelevant for that purpose.   
12 
 
 
We begin our analysis by examining the words of the statute.  For 
13 
convenience, we repeat them here: 
14 
 
"(1) A person commits the offense of driving while under the 
15 
influence of intoxicants if the person drives a vehicle while the person: 
16 
 
"(a) Has 0.08 percent or more by weight of alcohol in the blood of 
17 
the person as shown by chemical analysis of the breath or blood of the 
18 
person made under ORS 813.100, 813.140 or 813.150;  
19 
 
"(b) Is under the influence of intoxicating liquor, a controlled 
20 
substance or an inhalant; or 
21 
 
"(c) Is under the influence of any combination of intoxicating liquor, 
22 
an inhalant and a controlled substance." 
23 
 
 
We first observe that ORS 813.010(1) prohibits driving under the influence 
24 
of intoxicants:  "A person commits the offense of driving while under the influence of 
25 
 
7 
intoxicants if the person drives a vehicle while the person" is under the influence.  
1 
(Emphasis added.)  As this court stated in State v. Clark, 286 Or 33, 38, 593 P2d 123 
2 
(1979), quoting State v. Clark, 35 Or App 851, 856, 583 P2d 1142 (1978),  
3 
"'[t]he gravamen of [the predecessor statute to ORS 813.010] is driving 
4 
with a certain blood alcohol level.  The legislature has seen fit to forbid this 
5 
act, without more.'"   
6 
Thus, the focus of the statute is on the act of driving, and doing so while impaired.   
7 
 
 
The statute then sets out two ways to prove that a person drove while under 
8 
the influence of intoxicants:  The state can establish that the defendant's BAC was .08 
9 
percent or more, ORS 813.010(1)(a), regardless of observable symptoms, or the state can 
10 
prove that the person was "under the influence of intoxicating liquor, a controlled 
11 
substance, or an inhalant," that is, that the defendant was adversely affected by 
12 
intoxicants to a perceptible degree, ORS 813.010(1)(b), (c).  See King, 316 Or at 446 
13 
("The legislature did intend that a person could commit [the offense of DUII] by driving 
14 
with the specified BAC but with no perceptible impairment or by driving with a legally 
15 
permissible or unknown BAC but while nonetheless perceptibly impaired[.]"); Clark, 286 
16 
Or at 39 (in making it an offense to drive with a certain BAC, "the legislature apparently 
17 
assumed, based on scientific studies and medical knowledge, that the physical and mental 
18 
condition of a driver with such a level of blood alcohol is impaired to such a degree as to 
19 
make it unsafe for him to drive a motor vehicle, regardless of observable physical 
20 
symptoms").  Under either scenario, the state must prove that the driver had the 
21 
 
8 
proscribed BAC or was perceptibly impaired at the time that he or she was driving.6  
1 
ORS 813.010(1)(a), (b), and (c) (a person commits the offense of DUII "if the person 
2 
drives a vehicle while the person" has a BAC of 0.08 percent or more or was impaired).   
3 
 
 
This case requires us to consider how the state may prove that defendant 
4 
violated ORS 813.010(1)(a).  Under that statute, BAC at the time of driving must be 
5 
"shown by chemical analysis of the breath or blood."  (Emphasis added.)  However, it is 
6 
                                              
 
6 
In contrast, many other states explicitly require proof of a chemical test 
result over the legal limit at the time of the test or within a certain period of time after 
driving.  See, e.g., Alaska:  Alaska Stat § 28.35.030(2) (offense committed if driver has 
.08 percent BAC within four hours of driving); Arizona:  Ariz Rev Stat § 28-1381(2) 
(offense committed if driver has .08 percent BAC within two hours of driving); 
California:  Cal Veh Code § 23152(b) (rebuttable presumption of guilt if driver has .08 
percent BAC at time of test within three hours of driving); Delaware:  Del Code § 
4177(5) (offense committed if driver has .08 percent BAC or more within four hours of 
driving, "without regard to the person's alcohol concentration at the time of driving"); 
Kansas:  Kan Stat Ann § 8-1567(2) (offense committed if driver has .08 percent BAC 
within three hours of driving); Kentucky:  Ky Rev Stat Ann § 189A.010(1)(a) (offense 
committed if driver has .08 percent BAC at time of test within two hours of driving); 
Minnesota: Minn Stat § 169A.20, subd.1 (5) (offense committed if driver has .08 percent 
BAC as measured within two hours of driving); Montana:  Mont Code Ann § 61-8-
401(4)(c) (rebuttable inference of guilt if driver has .08 percent BAC at time of test); 
Nevada:  Nev Rev Stat § 484C.110(1)(c) (offense committed if driver has .08 percent 
BAC within two hours of driving); New Mexico:  NM Stat Ann § 66-8-102(C)(1) 
(offense committed if driver has .08 percent BAC within three hours of driving); North 
Dakota:  ND Cent Code § 39-08-01(1)(a) (offense committed if driver has .08 percent 
BAC at time of test within two hours of driving); Oklahoma:  Okla Stat § 47-11-902v 
(A)(1) (offense committed if driver has .08 percent BAC within two hours of driving); 
Pennsylvania:  Pa Cons Stat § 3802(a)(2) (offense committed if driver has .08 percent 
BAC within two hours of driving); Utah:  Utah Code Ann § 41-6a-502(1)(a) and (c) 
(offense committed if driver has .08 percent BAC at the time of the test or at the time of 
operating vehicle); Washington:  RCW § 46.61.502(1)(a) (offense committed if driver 
has .08 percent BAC within two hours of driving); Wyoming:  Wyo Stat Ann § 31-5-
233(b) (ii) (offense committed if driver has .08 percent BAC at time of driving or within 
two hours of driving). 
 
9 
virtually always the case that the chemical test of the breath or blood is administered 
1 
some time after the person has stopped driving.  That is so for several reasons.  First, a 
2 
breath test may not be administered until after the driver actually has been arrested for 
3 
DUII.  ORS 813.100(1) ("Any person who operates a motor vehicle  * * * shall be 
4 
deemed to have given consent * * * to a chemical test of the person's breath * * * for the 
5 
purpose of determining the alcoholic content of the person's blood if the person is 
6 
arrested for driving a motor vehicle while under the influence of intoxicants in violation 
7 
of ORS 813.010[.]").  In all cases, a certain amount of time will have passed after the stop 
8 
and before the arrest, while a police officer investigates the crime.  In addition, to test the 
9 
driver, the police officer must use a specific machine, the Intoxilyzer 5000 or the 
10 
Intoxilyzer 8000, which are the only breath test machines approved by the Oregon State 
11 
Police for use in performing a chemical analysis of a person's breath, OAR 257-030-
12 
0060; OAR 277-030-0120 (so stating), and which typically are located at the police 
13 
station.  Finally, before administering the test, the police officer must inform the person 
14 
of the consequences of refusing to take a breath test, ORS 813.100(1)(a), and then wait at 
15 
least 15 minutes to be certain that the person has not taken anything by mouth, vomited, 
16 
or regurgitated.  OAR 257-030-0070(2)(a) (Intoxilyzer 5000); OAR 257-030-0130(2)(a) 
17 
(Intoxilyzer 8000).   
18 
 
 
Importantly, a person's BAC changes during the time between being 
19 
stopped and undergoing a breath test.  Bessett testified at the hearing on defendant's 
20 
motion in limine that 80 percent of consumed alcohol enters the blood within five to 10 
21 
minutes, and 100 percent enters the blood within 30 to 60 minutes.  Moreover, as 
22 
 
10 
discussed above, alcohol is eliminated from the blood at a rate between .01 and .025 
1 
percent per hour.  It follows that a chemical test result alone never "shows" the actual 
2 
BAC of the driver at the time of driving.   
3 
 
 
Something more is necessary to connect the breath test result to the 
4 
statutory requirement of a BAC of .08 percent or more at the time of driving.  This court 
5 
has suggested that, when a breath test taken after the time of driving establishes a BAC of 
6 
.08 percent or higher, the trier of fact reasonably may infer the necessary connection.  
7 
That is, the jury may infer that the driver's BAC while driving was at least as high as the 
8 
later test result.  See State v. Parker, 317 Or 225, 232 n 9, 855 P2d 636 (1993) (stating, in 
9 
dictum, that, in case where the defendant had a BAC of .07 percent five hours after 
10 
driving, the state did not need to call an expert on the dissipation of blood alcohol 
11 
content, because the fact that blood alcohol dissipates over time is common knowledge).  
12 
In this case, defendant's breath test established a BAC at the time of the test of less than 
13 
the legal limit, at .064 percent.  The question here, then, is whether, in that circumstance, 
14 
the state may attempt to connect the breath test result to the statutory requirement of .08 
15 
percent BAC or more while driving with evidence that is not necessarily common 
16 
knowledge:  the precise rate of dissipation.   
17 
 
 
We conclude that the answer is yes.  As just discussed, ORS 813.010(1)(a) 
18 
provides that a person commits the offense of driving under the influence of intoxicants 
19 
if, while driving, the person "has 0.08 percent or more by weight of alcohol in the blood * 
20 
* * as shown by chemical analysis of the breath or blood[.]"  Because a breath test result 
21 
will never "show" a person's BAC at the exact time of driving, the state must be able to 
22 
 
11 
offer relevant evidence to explain how a driver's BAC at the time of the test "shows" that 
1 
he or she had .08 percent or more by weight of alcohol in the bloodstream at that earlier 
2 
point.  That is true whether the driver's BAC was exactly .08 percent, more than .08 
3 
percent, or less than .08 percent.  And an expert's testimony explaining retrograde 
4 
extrapolation, which uses a person's BAC at the time of the test to establish, based on a 
5 
scientific formula, that the person's BAC was above the legal limit at a certain earlier 
6 
time, is relevant and admissible for that purpose.  OEC 401 (evidence is relevant if it 
7 
makes any fact of consequence to the determination of the action more probable); OEC 
8 
402 (all relevant evidence is admissible unless otherwise provided). 
9 
 
 
Defendant nevertheless argues that, under ORS 813.010, a chemical 
10 
analysis, and only a chemical analysis, can "show" that a person drove while over the 
11 
legal limit.  However, as this court stated in Clark, if the legislature had intended for the 
12 
numerical breath test result to be the only evidence admissible under former ORS 
13 
487.540(1)(a), the predecessor statute to ORS 813.010(1)(a), it would have worded the 
14 
statute to make that limitation clear.7  286 Or at 44-45.  The court went on:  
15 
"[T]he more reasonable reading of the statute is that the driver must be 
16 
found in fact to have .10 percent blood alcohol [the legal limit at that time] 
17 
and that this must be shown by a chemical analysis.  In other words, the 
18 
state cannot establish a violation of [former] ORS 487.540(1)(a) without a 
19 
chemical analysis properly performed, but the analysis must 'show' the 
20 
actual presence of that percentage in the blood, not merely in the instrument 
21 
reading." 
22 
                                              
 
7 
And, as discussed above, at note 6, the DUII statutes of many other states 
clearly specify that the operative BAC is the driver's BAC at the time of the test.   
 
12 
Id. at 45 (emphasis in original).   
1 
 
 
The court in Clark addressed a somewhat different question than is 
2 
presented here:  whether a defendant was entitled to offer evidence, such as the testimony 
3 
of nonexpert witnesses relating to defendant's observable conduct, to impeach the 
4 
accuracy of the result of a chemical analysis.  Nonetheless, we think that the court's 
5 
reasoning in Clark is equally applicable in this case, where the state is the party seeking 
6 
to offer additional evidence to explain the results of the chemical analysis.  As the court 
7 
stated in Clark, the statute requires the chemical analysis to "show" the actual presence of 
8 
the alcohol in the blood at the time of driving; it does not merely require a certain 
9 
instrument reading.  That is, under the statute, the "chemical analysis" is the numerical 
10 
result that the machine produces together with an explanation of that result.  That 
11 
explanation can be simply an inference that blood alcohol rates dissipate over time, or, as 
12 
in this case, an expert's testimony explaining that retrograde extrapolation shows the 
13 
actual presence of the prohibited percentage of alcohol in a driver's blood when he or she 
14 
was driving.   
15 
 
 
Defendant contends, on the contrary, that this court, in State v. O'Key, 321 
16 
Or 285, 899 P2d 663 (1995), held that a chemical analysis is the "only" manner of 
17 
proving intoxication under ORS 813.010(1)(a).  Defendant is incorrect.  In O'Key, this 
18 
court held that evidence that the defendant failed a field sobriety test -- the horizontal 
19 
gaze nystagmus test -- was not admissible under ORS 813.010(1)(a) to prove that the 
20 
defendant, who had refused to take a breath test, drove with a BAC of .08 percent or 
21 
more.  The court held that 
22 
 
13 
"the offense of DUII with a .08 percent or more BAC may be proved only 
1 
by a 'chemical analysis of the breath or blood of the  person[.]'  * * *  An 
2 
HGN test does not involve a chemical analysis of breath or blood.  Hence, 
3 
an HGN test is not a chemical test under ORS 813.010(1)(a).  Under ORS 
4 
813.010(1)(a), HGN test evidence is not, therefore, admissible to prove that 
5 
a person had a BAC of .08 percent or more."   
6 
321 Or at 308 (emphasis in original).  It is, of course, true that an expert's testimony 
7 
explaining retrograde extrapolation also is not a "chemical test."  However, defendant 
8 
does not dispute that the state intends to offer a chemical test -- defendant's breath test 
9 
result -- showing that defendant had a BAC of .064 percent at the time of the test, to 
10 
prove that defendant drove while having a BAC of .08 percent or more.  Moreover, as the 
11 
Court of Appeals held below, Eumana-Moranchel, 243 Or App at450, and as we have 
12 
explained, the expert's retrograde extrapolation analysis is based on and derived from that 
13 
chemical test.  Thus, much as the observable conduct testimony in Clark explained that 
14 
the chemical test result did not "show" that the defendant drove with the prohibited BAC, 
15 
here, the retrograde extrapolation analysis, applied to the chemical test result, explains 
16 
that the chemical test "shows" that defendant drove with a BAC of .08 percent or more.   
17 
 
 
Context supports our conclusion that the legislature did not intend to 
18 
prohibit the state from introducing evidence, based on the breath test result, that a 
19 
person's BAC was over the legal limit at the time of driving.  First, in ORS 813.100, 
20 
Oregon's implied consent statute, the legislature expressly imposes various administrative 
21 
penalties on a driver whose BAC is over the legal limit at the time of the test.  ORS 
22 
813.100 provides, in part: 
23 
 
"(3)  If a person refuses to take a test under this section or if a breath 
24 
test under this section discloses that the person, at the time of the test, had 
25 
 
14 
a level of alcohol in the person's blood that constitutes being under the 
1 
influence of intoxicating liquor under ORS 813.300 [providing that a BAC 
2 
of .08 percent or more constitutes being under the influence of intoxicating 
3 
liquor], the person's driving privileges are subject to suspension under ORS 
4 
813.410 and the police officer shall [take certain enumerated actions.] 
5 
 
"(4)  If a blood test under this section discloses that the person, at the 
6 
time of the test, had a level of alcohol in the person's blood that constitutes 
7 
being under the influence of intoxicating liquor under ORS 813.300, the 
8 
person's driving privileges are subject to suspension under ORS 813.410 
9 
and the police officer shall report to the department within 45 days of the 
10 
date of arrest that the person failed the blood test." 
11 
(Emphasis added.)  The legislature's specificity in pointing to the time of the test in those 
12 
statutes suggests that, had the legislature intended the trier of fact to consider only a 
13 
person's BAC at the time of the breath test in determining whether a person has 
14 
committed the offense of driving while under the influence of intoxicants under ORS 
15 
813.010(1)(a), it could have done so by inserting the words "at the time of the test" into 
16 
ORS 813.010(1)(a).8 
17 
 
 
Second, ORS 813.300(1), which deals with the use of BAC as evidence, 
18 
also is consistent with our conclusion that evidence helping to explain that a person's 
19 
BAC was over the legal limit while he or she was driving is admissible under ORS 
20 
813.010(1)(a).  That statute provides:   
21 
"At the trial of any civil or criminal action, suit or proceeding arising out of 
22 
the acts committed by a person driving a motor vehicle while under the 
23 
influence of intoxicants, if the amount of alcohol in the person's blood at 
24 
the time alleged is less than 0.08 percent by weight of alcohol as shown by 
25 
chemical analysis of the person's breath or blood, it is indirect evidence that 
26 
                                              
 
8 
Those words are not found in ORS 813.010(1)(a) and we are, of course, 
admonished "not to insert what has been omitted."  ORS 174.010.      
 
15 
may be used with other evidence, if any, to determine whether or not the 
1 
person was then under the influence of intoxicants." 
2 
(Emphasis added.)  That statute describes the use of evidence at trial in a case "arising out 
3 
of the acts committed by a person driving a motor vehicle while under the influence of 
4 
intoxicants," including, as relevant here, a prosecution for DUII.  Under that statute, if a 
5 
person's BAC "at the time alleged" is less than .08 percent as shown by a chemical 
6 
analysis of the person's breath or blood, it is indirect evidence that may be used with 
7 
other evidence to prove that the person was under the influence of intoxicants.  Because 
8 
the "gravamen of [ORS 813.010] is driving with a certain blood alcohol level," Clark, 
9 
286 Or at 38, the reference in ORS 813.300(1) to "the amount of alcohol in the person's 
10 
blood at the time alleged" (emphasis added) is a reference to BAC at the time of driving.  
11 
However, as we already have explained, the "chemical analysis of the person's breath" -- 
12 
the breath test -- does not prove the amount of alcohol in the person's blood at the time of 
13 
driving.  Retrograde extrapolation is the mechanism by which the amount of alcohol in a 
14 
person's blood at the time alleged is "shown" to be more or less than 0.08 percent.9  It 
15 
provides the necessary connection between evidence of a person's BAC at the time of the 
16 
test and his or her BAC while driving.10   
17 
                                              
 
9 
And it follows that, if retrograde extrapolation shows that a person's BAC 
at the time of driving was less than .08 percent, then, under ORS 813.300(1), the driver's 
BAC still is admissible as indirect evidence that may be used with other evidence to 
prove that the driver was under the influence of intoxicants.   
 
10 
Both defendant and the state contend that legislative history supports their 
respective positions.  However, neither party has pointed to any legislative history 
 
 
16 
 
 
We hold that the state should have been permitted to offer the expert's 
1 
testimony explaining retrograde extrapolation to establish that defendant's BAC was over 
2 
.08 percent at the time he was driving.   
3 
 
 
The decision of the Court of Appeals is affirmed.  The judgment of the 
4 
circuit court is reversed, and the case is remanded to the circuit court for further 
5 
proceedings.
6 
                                              
showing that the legislature actually considered whether expert testimony explaining to 
the jury the relationship between a BAC test result and a defendant's BAC some time 
earlier, at the time of driving, would be admissible.  Nor has either party identified any 
legislative history suggesting that the legislature intended that the state's ability to convict 
a driver under ORS 813.010(1)(a) would depend only on the driver's BAC at the time of 
the test.  In short, nothing in the legislative history suggests that the legislature had any 
express intention to require the state to prove BAC only with the numerical result of a 
breath test taken at some point after the person stopped driving.   
 
1 
 
 
DE MUNIZ, J., dissenting. 
1 
 
 
Although the only chemical analysis conducted in this case showed a blood 
2 
alcohol content (BAC) of .064 percent, the majority opinion goes to great lengths to 
3 
avoid the plain meaning of the term "chemical analysis" in ORS 813.010(1)(a) in order to 
4 
permit the state to use retrograde extrapolation to prove that defendant drove while his 
5 
BAC was over .08 percent.  Because I conclude that the legislature enacted ORS 
6 
813.010(1)(a) as a bright-line rule intended to include only those persons who actually 
7 
register a BAC of .08 percent or greater on a chemical test, I respectfully dissent.   
8 
 
 
When prosecuting a DUII, the state ordinarily may proceed under either 
9 
paragraph (a) or (b) of ORS 813.010(1) (or both, in the alternative) -- that is, the state 
10 
may convict the defendant by proving either that the defendant drove with a BAC of .08 
11 
percent or more "as shown by chemical analysis," or that the defendant was "under the 
12 
influence of intoxicating liquor."  However, because of the limited procedural posture of 
13 
this case, we consider the use of retrograde extrapolation only as it applies to paragraph 
14 
(a) of ORS 813.010(1).  Nothing in this opinion affects the use of that evidence under 
15 
paragraph (b), as evidence of actual impairment at the time of driving.  As a practical 
16 
matter, then, the only case in which the state would require that evidence to secure a 
17 
conviction is when a person both has a BAC lower than .08 percent when tested and has 
18 
exhibited no outward signs of impairment sufficient to convict under paragraph (b).  The 
19 
majority holds that, in that situation, the statute permits the state to convict on the basis of 
20 
expert testimony extrapolating from the results of a chemical analysis by factoring in 
21 
additional, nonchemical evidence regarding mathematical formulas, average dissipation 
22 
 
2 
rates,1 and the time defendant last consumed alcohol and last drove, in direct 
1 
contradiction to the statute's directive that BAC may be proved only "by chemical 
2 
analysis."  In my view, the more logical explanation is that the legislature simply 
3 
intended for a person in that position to be acquitted.  As I discuss in more detail below, 
4 
both the structure of the statute and the plain meaning of its text requiring the requisite 
5 
minimum BAC to be "shown by chemical analysis" support that conclusion.   
6 
 
 
As I interpret it, the structure of the statute indicates that there is only one 
7 
crime -- driving under the influence of intoxicants -- for which the legislature has 
8 
provided two methods of proof.  The first method of proof is to secure a chemical 
9 
analysis showing a BAC above .08 percent.  The second method of proof is to prove 
10 
beyond a reasonable doubt that the defendant's driving was actually impaired by the 
11 
consumption of alcohol.  By contrast, the majority's interpretation has created an 
12 
additional crime of driving with a BAC above .08 percent, the elements of which the state 
13 
                                              
 
1 
The mathematical formulas used in the kind of retrograde extrapolation 
performed in this case were not specifically tailored to the defendant, but were derived 
from studies of average alcohol dissipation rates across a broad population.  As the state's 
expert admitted, those rates can vary widely from person to person, preventing the 
analysis from determining what defendant's specific BAC was at the time of driving.  
Rather, the tests can return only a "range" of possible results, which, as the state's expert 
testified, will be accurate for only 98 out of 100 people.  __ Or at __ n 3 (slip op at 4 n 3).  
In my view, using those averages and calculations that are not specific to defendant's 
particular physiology and circumstances directly contravenes the statutory text that the 
subject of the "chemical analysis" must be the breath or blood of the defendant.  ORS 
813.010(1)(a).   
 
3 
may establish by whatever means it pleases.2  After today, the state need not be bothered 
1 
to try to prove that any defendant's driving was actually impaired (the actual wrongful 
2 
conduct intended to be punished), unless the defendant's BAC, when tested, was so low 
3 
that by no possible "range" of extrapolation could the defendant's BAC ever have 
4 
exceeded .08 percent.    
5 
 
 
Because the first method of proof provided in paragraph (a) is a type of 
6 
evidentiary presumption -- a means by which the state is permitted to prove the 
7 
commission of the offense without proving the actual underlying wrongful conduct -- it 
8 
would make sense for the legislature to limit the means of establishing that presumption 
9 
to a method erring slightly on the side of under inclusivity.  By limiting the use of 
10 
paragraph (a) to those defendants who manifest a .08 percent BAC or higher at the time 
11 
of the test, paragraph (a) of the statute is under inclusive as to those persons who may 
12 
have been at or slightly over .08 percent BAC at the time of driving, but whose BAC has 
13 
dissipated to below .08 percent by the time of the test.  However, the state may still opt to 
14 
                                              
 
2 
It is no defense to the majority's position that the retrograde extrapolation 
analysis is "based" on a chemical analysis.  There is no way to arrive at any known 
percentage of blood alcohol content -- as the statute requires -- without some reference to 
a chemical analysis.  The inclusion of the additional requirement in the statute that the .08 
percent must be "shown by chemical analysis of the breath or blood of the person made 
under ORS 813.100, 813.140 or 813.150" is better understood not as redundant to that 
obvious truth but rather as limiting the universe of methods by which the state is 
permitted to prove the defendant's precise blood alcohol content.  That limitation 
necessarily implies that there are other ways to prove that defendant's blood contained 
.08 percent alcohol at the time of driving; however, only those ways expressly listed are 
admissible to satisfy the evidentiary presumption provided by paragraph (a).   
 
4 
prosecute those defendants under paragraph (b) by proving that their driving was actually 
1 
impaired.  Indeed, the state may still introduce its retrograde extrapolation evidence to 
2 
demonstrate how much higher the defendant's BAC likely was at the time of the crime, in 
3 
conjunction with any other evidence tending to prove impairment.  That interpretation of 
4 
the statute, in which paragraph (a) may be used to establish a presumption of impairment 
5 
in the most clear-cut cases, while paragraph (b) is used to ensure that in borderline cases 
6 
wrongful conduct is established beyond a reasonable doubt, reliably encompasses the 
7 
harm sought to be proscribed while adequately balancing the interests of both defendants 
8 
and the state. 
9 
 
 
On the other hand, if, as the majority holds, retrograde extrapolation 
10 
standing alone is sufficient to establish a violation of the statute, the statute risks over 
11 
inclusivity, because there is no limit to how far the state may extrapolate to secure a 
12 
conviction.  The majority's interpretation would permit the state to prove through 
13 
retrograde extrapolation not only that a person with a .07 percent BAC was over .08 
14 
percent one hour earlier, but also that a person with a .01 percent BAC was over .08 
15 
percent eight hours earlier.  The scientific principles supporting retrograde extrapolation 
16 
have not advanced to such a state today -- and certainly had not in 1975 when the 
17 
legislature first enacted this statute -- to permit such a conviction beyond a reasonable 
18 
doubt.  Indeed, in 1975, a first offense for driving under the influence of intoxicants was 
19 
a mere traffic infraction, punishable by fine only, not to exceed $1,000.  See former ORS 
20 
487.540(2) (1975), repealed by Or Laws 1983, ch 338, § 978 (providing that "[d]riving 
21 
while under the influence of intoxicants is a Class A traffic infraction"); former ORS 
22 
 
5 
484.360(1), (2) (1975), repealed by Or Laws 1983, ch 338, § 978 (providing that "the 
1 
penalty for committing a traffic infraction shall be a fine only," which, for Class A traffic 
2 
infractions, may not exceed $1,000).  It can hardly be contended that in that context the 
3 
1975 legislature could have envisioned a battle of competing scientific expert witnesses 
4 
at a full-blown criminal trial testifying with regard to science that, if it existed at all, was 
5 
in its very nascence.  That the legislature intended to create a simple, bright-line 
6 
evidentiary presumption is more plausible in that context. 
7 
 
 
The plain meaning of the text of the statute also supports my conclusion 
8 
that the legislature had no intention of including retrograde extrapolation as a "chemical 
9 
analysis" under paragraph (a).  The legislature required that a BAC of .08 percent or more 
10 
must be "shown by chemical analysis of the breath or blood of the person" in order to 
11 
support a determination that a person has committed the offense of driving under the 
12 
influence under ORS 813.010(1)(a).  The legislature did not provide that a BAC of less 
13 
than .08 percent, as shown by chemical analysis, could somehow be rehabilitated or 
14 
explained away by expert testimony or any other circumstantial evidence under 
15 
paragraph (a).  The terms the legislature used in paragraph (a) plainly require that a 
16 
chemical analysis made under ORS 813.100, ORS 813.140, or ORS 813.150 must itself 
17 
show that a person has a BAC of .08 percent or greater.  That reading of the text is well 
18 
supported by the applicable definitions of the terms the legislature used in the statute and 
19 
by the general rules of grammatical construction that inform our understanding of 
20 
statutory terms. 
21 
 
 
 The statutory phrase, "as shown by chemical analysis of the breath or 
22 
 
6 
blood of the person made under ORS 813.100, 813.140 or 813.150," when broken down 
1 
into its significant constituent parts, provides the following construct.  "Shown" is the 
2 
past participle of the verb "show," and the synonyms for the general term "show" are as 
3 
follows: 
4 
"syn EVINCE, MANIFEST, EVIDENCE, DEMONSTRATE: in this series 
5 
SHOW is a general term, usu. interchangeable with any of the others, for 
6 
indicating, revealing, displaying[.]" 
7 
Webster's Third New Int'l Dictionary 2105 (unabridged ed 2002).  "Chemical" means: 
8 
"3 : having reference to or relating to the science of chemistry[.]"  Id. at 383.  "Analysis," 
9 
in the context of chemistry, means: 
10 
"4 a : the separation of compound substances into their constituents by 
11 
chemical processes b : the determination, which may or may not involve 
12 
actual separation, of one or more ingredients of a substance either as to kind 
13 
or amount; also : the tabulated result of such a determination[.]" 
14 
Id. at 77.  Thus, the phrase "as shown by chemical analysis of the breath or blood of the 
15 
person" most directly and most reasonably is read to mean the result demonstrated by the 
16 
chemical test itself. 
17 
 
 
That point is made even more evident by the legislature's explicit 
18 
articulation of the three specific ways in which a person's BAC may be "shown" under 
19 
paragraph (a):  by a chemical analysis "made under ORS 813.100, 813.140 or 813.150."  
20 
Those statutory provisions provide for the administration of chemical tests of the 
21 
defendant's breath, blood, or urine -- without mention of any kind of extrapolation or 
22 
extrinsic interpretation of the results of those tests.  In limiting the chemical analyses that 
23 
can be used to those "made" under those statutes, the legislature specified a manner of 
24 
 
7 
proof -- a specific type of test with a specific result.  It is the office of this court to 
1 
ascertain and declare what is contained within the substance of the statute -- not to insert 
2 
what may have been omitted or to second-guess the policy choices made by the 
3 
legislature.  See ORS 174.010 (providing that "[i]n the construction of a statute, the office 
4 
of the judge is simply to ascertain and declare what is, in terms or in substance, contained 
5 
therein, not to insert what has been omitted.").  Whether or not we think that modern 
6 
retrograde extrapolation analysis may be a reliable and convenient manner of proving a 
7 
defendant's BAC at the time of driving, it is not for us to add a fourth method to the three 
8 
the legislature saw fit to permit.  Consequently, I determine that we should take the terms 
9 
the legislature enacted in ORS 813.010(1)(a) at face value and adhere to the policy choice 
10 
that the legislature made in setting out the specific manner for proving a violation of the 
11 
statute. 
12 
 
 
The legislative history of the statute also supports that interpretation.  As 
13 
the majority notes, the legislative history of ORS 813.010(1)(a) provides little direct 
14 
enlightenment regarding whether the legislature ever actually considered the problem of 
15 
dissipation in the interim between the time of driving and the time of a chemical analysis.  
16 
__ Or at __ (slip op at 15 n 10).  But what little legislative history we do have on the 
17 
subject is at least consistent with, if not supportive of, a more restrictive reading of ORS 
18 
813.010(1)(a) than the majority allows. 
19 
 
 
The text "as shown by chemical analysis" was initially enacted in former 
20 
ORS 487.540(1)(a) (1975), repealed by Or Laws 1983, ch 338, § 978, as part of a 
21 
comprehensive overhaul of Oregon's motor vehicle laws, which included changes to 
22 
 
8 
Oregon's DUII laws.3  Prior to enacting that statute, the Committee on the Judiciary, 
1 
which prepared the Motor Vehicle Code and the text of former ORS 487.540(1)(a), 
2 
discussed the evidentiary problems that alcohol absorption and elimination could create 
3 
in DUII prosecutions.  According to the committee minutes, then-Solicitor General W. 
4 
Michael Gillette testified before the committee regarding the problem with time lapses in 
5 
chemical analyses in the following terms: 
6 
"[Gillette's] concern was that the trier of fact had been told that some use 
7 
could be made of a blood alcohol content of .08 percent and lower as 
8 
indirect evidence but he was not told what to do with evidence of .08 
9 
percent or higher.  In addition to instructions as to what to do when the 
10 
evidence was less than .08, his proposal would give the courts direction as 
11 
to what to do when the analysis showed more than .08.  He pointed out that 
12 
the blood test was not contemporaneous with the driving; the test results 
13 
were established at a later time.  His answer to this problem as set out in his 
14 
proposed revision * * * was that a person who was shown to have .08 
15 
percent or higher at the time of the blood test was at least then under the 
16 
influence, and from there it could be inferred backward that he was under 
17 
the influence at the earlier time, even though the court could not be certain 
18 
that his blood alcohol content at the time of driving was .08." 
19 
Minutes, Committee on Judiciary, Sept 24, 1974, 7 (emphasis added).  That statement 
20 
highlights that the proposed answer to the evidentiary problems that alcohol absorption 
21 
and elimination could create was to provide that, once a person is shown to have a BAC 
22 
                                              
 
3 
Although former ORS 487.540 was repealed by Or Laws 1983, ch 338, § 
978, the legislature's intent with regard to that provision presumably applies with equal 
force to ORS 813.010(1)(a), which was enacted by a different section of that same 
chapter and contained substantially the same text.  The legislature explicitly provided that 
"[i]t is not the purpose or intent of the Oregon Legislative Assembly to change the law by 
enacting the revision of the Oregon Vehicle Code contained in chapter 338, Oregon Laws 
1983."  Or Laws 1983, ch 338, § 3. 
 
9 
of .08 percent or higher at the time of the test, it can be inferred backward that the person 
1 
must have had a BAC no lower than .08 percent at the time of driving -- even though the 
2 
court could not be certain of the defendant's precise BAC at the time of driving.4  That 
3 
theory is consistent with the language of the statute actually enacted by the legislature, 
4 
requiring BAC to be proved under paragraph (a) "by chemical analysis,"5 and also 
5 
comports with the additional provisions enacted by the legislature as former ORS 
6 
487.545(1) and (2) (1975).6  Former ORS 487.545(1) specifically provided that the 
7 
                                              
 
4  
Solicitor General Gillette's testimony referred to a BAC of .08 percent.  The 
legislature initially enacted provisions in former ORS 487.545 (1975), repealed by Or 
Laws 1983, ch 338, § 978, and former ORS 487.540 (1975), that set the legal 
presumption of intoxication at .10 percent BAC.  The legislature then later modified the 
standard to .08 percent BAC, as it is currently set out in ORS 813.300 and in ORS 
813.010.  Those changes in the BAC standard, however, do not affect the central issue in 
this case.   
 
5  
Former ORS 487.540(1)(a) (1975) provided: 
 
"A person commits the offense of driving while under the influence 
of intoxicants if he drives a vehicle while: 
 
"(a) He has .10 percent or more by weight of alcohol in his blood as 
shown by chemical analysis of his breath, blood, urine or saliva made under 
ORS 487.805 to 487.815 and 487.825 to 487.835[.]" 
 
6 
Former ORS 487.545(1) and (2) provided: 
 
"(1) At the trial of any civil or criminal action, suit or proceeding 
arising out of the acts committed by a person driving a motor vehicle while 
under the influence of intoxicants, if the amount of alcohol in the person's 
blood at the time alleged is less than .10 percent by weight of alcohol as 
shown by chemical analysis of the person's breath, blood, urine or saliva, it 
is indirect evidence that may be used to determine whether or not he was 
then under the influence of intoxicants. 
 
 
10 
appropriate use of a BAC lower than the legal limit (then .10 percent), "as shown by 
1 
chemical analysis," was as "indirect evidence that may be used to determine whether or 
2 
not [defendant] was then under the influence of intoxicants."  By contrast, former ORS 
3 
487.545(2) provided that a BAC over the legal limit "constitutes being under the 
4 
influence of intoxicating liquor."  
5 
 
 
Consistent with that legislative history, all of the statutory provisions can be 
6 
given full effect by determining that the requisite proof for a prosecution under ORS 
7 
813.010(1)(a) is a chemical breath or blood test showing a BAC of .08 percent or higher 
8 
and determining that a chemical test showing a BAC lower than .08 percent constitutes 
9 
only indirect evidence that the person is under the influence of intoxicants for 
10 
prosecutions under ORS 813.010(1)(b) or (c).  Those determinations, of course, lead 
11 
ineluctably to the conclusion that a chemical test showing a BAC lower than .08 percent 
12 
cannot establish that a person drove with a BAC of .08 percent or higher, and any 
13 
                                              
 
"(2) Not less than .10 percent by weight of alcohol in a person's 
blood constitutes being under the influence of intoxicating liquor." 
 
 
ORS 813.300(1) and (2) now provide: 
 
"(1) At the trial of any civil or criminal action, suit or proceeding 
arising out of the acts committed by a person driving a motor vehicle while 
under the influence of intoxicants, if the amount of alcohol in the person's 
blood at the time alleged is less than 0.08 percent by weight of alcohol as 
shown by chemical analysis of the person's breath or blood, it is indirect 
evidence that may be used with other evidence, if any, to determine 
whether or not the person was then under the influence of intoxicants. 
 
"(2) Not less than 0.08 percent by weight of alcohol in a person's 
blood constitutes being under the influence of intoxicating liquor." 
 
11 
testimony about the import of such a test result (based upon retrograde extrapolation or 
1 
any other theory) is not relevant for purposes of determining whether the person violated 
2 
ORS 813.010(1)(a). 
3 
 
 
Furthermore, this determination also comports with the prior decisions of 
4 
this court.  In State v. O'Key, 321 Or 285, 308, 899 P2d 663 (1995), this court stated that 
5 
"the offense of DUII with a .08 percent or more BAC may be proved only by a 'chemical 
6 
analysis of the breath or blood of the person made under ORS 813.100, 813.140 or 
7 
813.150.'"  (Emphasis in original.)  The majority correctly notes that the precise issue 
8 
addressed by this court in O'Key was limited to whether the horizontal gaze nystagmus 
9 
(HGN) test was admissible under ORS 813.010(1)(a) to prove that the defendant drove 
10 
with a BAC of .08 percent or more, but I think it significant that this court described the 
11 
universe of available proof under ORS 813.010(1)(a) as limited to a chemical analysis of 
12 
the breath or blood.  The majority opinion distinguishes in this case between an HGN 
13 
test, which is clearly not a chemical test, and testimony concerning retrograde 
14 
extrapolation, which the majority concludes is derived from a chemical test.  __ Or at __ 
15 
(slip op at 12-13).  But in doing so, the majority opinion acknowledges, as it must, that 
16 
testimony explaining retrograde exploitation analysis is not a chemical test.  Id.  And that 
17 
is where we draw different lines.  While the majority opinion concludes that testimony 
18 
concerning retrograde extrapolation is admissible to prove a violation of ORS 
19 
813.010(1)(a), despite the fact that the majority agrees that testimony about retrograde 
20 
extrapolation is not a chemical test that shows the BAC of the defendant, I conclude, in 
21 
harmony with this court's express statement in O'Key, that only a chemical test that shows 
22 
 
12 
that the BAC of the defendant was .08 percent or more at the time of the test is 
1 
admissible to prove such a violation. 
2 
 
 
The majority also relies in part on this court's decision in State v. Clark, 286 
3 
Or 33, 593 P2d 123 (1979), for support.  __Or at __ (slip op at 11).  The only issue 
4 
directly presented in Clark, however, was defendant's right to attack the validity and 
5 
accuracy of the chemical test result that showed that defendant had a BAC of .10 percent 
6 
or more under former ORS 487.540.  The narrow issue decided by this court in Clark was 
7 
that, 
8 
"because the 'chemical analysis' of the blood test of this defendant by the use of a 
9 
Breathalyzer could 'produce invalid results through human error or chemical or 
10 
mechanical defect,' the defendant was entitled to attempt to impeach the accuracy of the 
11 
testimony of the expert witness relating to the results of that test by any competent 
12 
evidence." 
13 
286 Or at 43.  Here, of course, the testimony that the state wished to present concerning 
14 
retrograde extrapolation was not in any way intended to impeach the accuracy of the 
15 
chemical test result; indeed, the testimony necessarily relied upon the accuracy of the 
16 
chemical test result that showed that defendant's BAC was .064 percent (well below the 
17 
statutory standard of .08 percent).  Nothing expressed by this court in Clark addresses the 
18 
issue presented in this case -- viz., whether evidence that is unrelated to the accuracy of 
19 
the chemical test result is admissible in a prosecution under ORS 813.010(1)(a). 
20 
 
 
Finally, the majority also notes this court's decision in State v. Parker, 317 
21 
Or 225, 855 P2d 636 (1993).  __ Or at __ (slip op at 10).  In Parker, however, there was 
22 
 
13 
no distinction drawn between a prosecution pursued under ORS 813.010(1)(a) and 
1 
prosecutions pursued under ORS 813.010(1)(b) and (c).  See Parker, 317 Or at 227 
2 
(noting that defendant was charged with driving under the influence under ORS 813.010 
3 
generally).  The court then merely noted in passing, in addressing the propriety of a 
4 
denial of a request for a continuance, that in a prosecution brought under ORS 813.010 
5 
the state could rely upon the common knowledge that blood alcohol dissipates over time, 
6 
and that defendant could have prepared to address that issue whether or not the state gave 
7 
timely notice of its intent to present expert testimony on the matter.  Id. at 232 n 9.  In 
8 
addition, while this court did also refer to the fact that there was expert testimony 
9 
presented to establish that defendant's BAC was greater than .08 percent at the time of the 
10 
accident, based upon a breath test result showing a BAC of .07 percent more than five 
11 
hours later, that discussion is of no moment here, because the admissibility of that 
12 
evidence in a prosecution pursued solely under ORS 813.010(1)(a) was not presented or 
13 
decided in Parker.  Consequently, this court's decision in Parker is also inapposite to the 
14 
issue presented in this case. 
15 
 
 
As discussed above, I conclude that the text and legislative history establish 
16 
that the legislature intended prosecutions under ORS 813.010(1)(a) to rely only on 
17 
chemical test results showing that the defendant had a BAC of .08 percent or more at the 
18 
time of the test.  I also conclude that that interpretation of ORS 813.010(1)(a) is 
19 
consistent with, and not precluded by, this court's prior decisions.  Consequently, I would 
20 
hold that the trial court properly excluded the retrograde extrapolation testimony 
21 
proffered by the state.  I respectfully dissent, therefore, from the contrary determination 
22 
 
14 
reached by the majority. 
1 
 
 
Durham and Walters, JJ., join this opinion. 
2 
 
3