      TEXAS COURT OF APPEALS, THIRD DISTRICT, AT AUSTIN


                                      NO. 03-04-00070-CR



                                  James W. Knight, Appellant

                                                 v.

                                  The State of Texas, Appellee




             FROM THE COUNTY COURT AT LAW NO. 6 OF TRAVIS COUNTY
              NO. 632,326, HONORABLE JAN BRELAND, JUDGE PRESIDING



                            MEMORANDUM OPINION


               Appellant James Knight was charged by information with the class B misdemeanor

offense of driving while intoxicated. See Tex. Pen. Code Ann. § 49.04 (West 2003). After his

motion to suppress was denied, he entered into a plea agreement with the State. In two issues, he

appeals the trial court’s denial of his motion to suppress the results of his breath tests. We will

affirm the judgment of conviction.


                                        BACKGROUND

               The parties stipulated to the following facts. On January 24, 2003, at approximately

2:51 a.m., Department of Public Safety trooper Mike Reisen initiated a traffic stop that resulted in

Knight’s arrest. Knight initially told Reisen that he had consumed two beers. After taking the field
sobriety tests, however, Knight admitted that he had consumed two beers as well as a rum and coke

mixed drink. Although Knight told Reisen that he had last eaten at approximately 7 p.m., Reisen

did not determine what time the first or last drink was consumed or over what period of time Knight

had been drinking. Reisen was also not aware of the pattern in which the drinks had been consumed

or the type and quantity of food that Knight had consumed. Reisen performed a breath test of Knight

at approximately 3:56 a.m. in which Knight’s blood alcohol content was 0.108. In another breath

test performed at 3:59 a.m., Knight’s blood alcohol content was 0.102. Although Reisen did not

know Knight’s weight on the date of arrest, Knight’s driver’s license stated that he weighed 160

pounds at the time of the issuance of the license.1

                Knight was arrested and charged with driving while intoxicated. The State alleged

that he was intoxicated under both definitions of intoxication: (A) not having the normal use of

mental or physical faculties by reason of the introduction of alcohol; and (B) having an alcohol

concentration of 0.08 or more. See id. § 49.01 (West 2003).

                Knight filed a motion to suppress “the results of the breath test and its admission into

evidence in the State’s case in chief because the State is unable to provide sufficient reliable and

supporting evidence of the Defendant’s alcohol level at the time of driving.” Alvin Weathermon,

a senior forensic chemist for the Austin Police Department, conducted a retrograde extrapolation

analysis to determine Knight’s blood-alcohol level at the time he was driving.2 Weathermon then

       1
           There is no evidence in the record regarding when the license was issued.
       2
         Retrograde extrapolation is the computation back in time of the blood-alcohol level—the
estimation of the level at the time of driving based on a test result from some later time. Mata v.
State, 46 S.W.3d 902, 908-09 (Tex. Crim. App. 2001). Due to the fact that tests revealing a
defendant’s blood-alcohol level are taken at some point after the defendant was driving, prosecutors

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testified at the suppression hearing about how he conducted his tests and what factors he used.

However, Weathermon never articulated the results of the test and did not give an opinion regarding

whether Knight was legally intoxicated at the time he was driving.

               The trial court denied Knight’s motion to suppress and, pursuant to a plea agreement,

Knight pleaded guilty. He was sentenced to 120 days’ confinement and a fine of $1,400. Imposition

of the sentence was suspended and Knight was placed on community supervision for eighteen

months. This appeal followed.


                                          DISCUSSION

Standard of review

               When we review a trial court’s ruling on a motion to suppress, we give great

deference to the court’s determination of historical facts while reviewing its application of the law

de novo. Maxwell, 73 S.W.3d at 281. We review the ruling on a motion to suppress evidence for

an abuse of discretion. Swain v. State, No. AP-74,854, 2005 Tex. Crim. App. LEXIS 1864, at *12

(Tex. Crim. App. Nov. 2, 2005) (citing Balentine v. State, 71 S.W.3d 763, 768 (Tex. Crim. App.

2002)). Because no findings of fact were filed in this case, we view the evidence in a light most



sometimes use retrograde extrapolation testimony to prove that the defendant was actually driving
while he was intoxicated.

          The court of criminal appeals has discussed in great detail how alcohol is absorbed into and
eliminated from the blood stream. See id. at 909-11. “If a driver is tested while in the absorption
phase, his BAC [blood-alcohol content] at the time of the test will be higher than his BAC while
driving. If tested while in the elimination phase, his BAC at the time of the test could be lower than
while driving, depending on whether he had reached his peak before or after he was stopped.
Obviously, the greater the length of time between the driving and the test, the greater the potential
variation between the two BACs.” See id.

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favorable to the trial court’s ruling and assume that the court made implicit findings of fact that

support its ruling, as long as the findings are supported by the record. See Swain, 2005 Tex. Crim.

App. LEXIS 1864, at *12; Romero v. State, 800 S.W.2d 539, 543 (Tex. Crim. App. 1990).


Application

                  Knight’s motion to suppress only challenges the admissibility of his breath test

results.     However, his challenge to their admissibility is two-fold.         First, he argues that

Weathermon’s retrograde extrapolation testimony was unreliable because Weathermon lacked

sufficient information to conduct a scientifically accurate test. Next, he argues that reliable

retrograde extrapolation testimony was necessary to support the admissibility of the breath tests. For

convenience, we will first consider Knight’s second argument—that without retrograde extrapolation

testimony, his breath test results were inadmissible and should have been suppressed.

                  Breath test results that reveal a defendant’s intoxication level tend to make it more

probable that the defendant was intoxicated at the time he drove under either definition of

intoxication, see Tex. Pen. Code Ann. § 49.04, because they provide evidence that he had consumed

alcohol. Stewart v. State, 129 S.W.3d 93, 96 (Tex. Crim. App. 2004). Knight argues that “contrary

to the court of criminal appeals decision in Stewart, retrograde extrapolation evidence is an

indispensable and necessary part of the relevancy of breath test results” and that the facts in his case

are distinguishable from those in Stewart. We disagree.

                  In Stewart, the court noted that


           [t]he admission of the breath test results did not necessarily encourage the jury to
           engage in its own crude retrograde extrapolation because the jury did not need to

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        establish Stewart’s exact blood alcohol concentration at the time that she drove. The
        jury only needed to believe beyond a reasonable doubt that either her blood alcohol
        concentration was 0.10 or more, or that she failed to have the normal use of her
        mental or physical facilities by reason of introduction of alcohol into her body, at the
        time she drove. The breath test results were properly admitted evidence to consider
        with all of the other evidence of intoxication to determine if Stewart was intoxicated
        at the time she drove.


Id. at 97. Knight argues that “giving the trier of fact specific test results that cannot be linked back

to the relevant point in time is far different than telling the trier of fact that a breath test showed that

the accused had consumed alcohol.” However, we are bound by the court’s holding in Stewart that

retrograde extrapolation testimony is not required to render breath tests admissible. See id. at 97-98;

see also Mechler v. State, 153 S.W.3d 435, 440 (Tex. Crim. App. 2005) (analyzing admissibility of

intoxilyzer results under rule of evidence 403). Furthermore, Knight’s allegation that there were

more facts surrounding Stewart’s intoxication than are present in Knight’s case does not render the

results of his breath tests inadmissible. The trial court did not abuse its discretion in denying the

motion to suppress. We overrule Knight’s second issue.

                In his first issue, Knight argues that the retrograde extrapolation testimony should

have been suppressed because Weathermon did not have sufficient information to reliably conduct

a retrograde extrapolation. As we have already discussed, under Stewart, retrograde extrapolation

testimony is not necessary to render the breath tests admissible. Stewart, 129 S.W.3d at 97-98.

Furthermore, Weathermon did not testify that Knight was intoxicated at the time he drove or

otherwise reveal any results of Weathermon’s analysis of Knight’s blood alcohol level. There is no

evidence in the record that Weathermon’s testimony would have supported a finding that Knight was

intoxicated. Therefore, Knight has failed to demonstrate that Weathermon’s testimony, even if it

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was unreliable, would have prejudiced him. See Gonzales v. State, 966 S.W.2d 521, 524 (Tex. Crim.

App. 1998) (if record does not demonstrate that evidence sought to be suppressed has “somehow

been used” by the State, appellate court need not address merits of claim); see also Gonzales v. State,

977 S.W.2d 189, 190-91 (Tex. App.—Austin 1998, pet. ref’d) (record did not show that results of

analysis revealed incriminating evidence). We overrule Knight’s first issue.


                                          CONCLUSION

               Having overruled Knight’s issues, we affirm the judgment of conviction.




                                               W. Kenneth Law, Justice

Before Chief Justice Law, Justices Patterson and Puryear

Affirmed

Filed: February 2, 2006

Do Not Publish




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