Opinion filed October 21, 2010




                                           In The


   Eleventh Court of Appeals
                                         __________

                                    No. 11-09-00059-CR
                                        __________

                                 GROVER SIMS, Appellant

                                               V.

                                 STATE OF TEXAS, Appellee



                            On Appeal from 385th District Court

                                    Midland County, Texas

                                 Trial Court Cause No. CR35166


                           MEMORANDUM OPINION
       The jury convicted Grover Sims of felony driving while intoxicated and assessed his
punishment at twelve years confinement and a $10,000 fine. Sims argues that the trial court
abused its discretion by allowing a police officer to testify as an expert witness. We affirm the
trial court’s judgment.
       The State called Midland Police Sergeant Craig Matthews as an expert witness. Sergeant
Matthews testified that he had attended the Standardized Field Sobriety Testing School, the Drug
Impaired Training for Educational Professionals Course, the Behavior Recognition for
Educational Professionals Course, the Drug Recognition Expert Instructor Course, and the
Advanced Roadside Impaired Driving Enforcement Course. Sergeant Matthews testified that he
was now an instructor for each of these courses. The State then offered Sergeant Matthews as an
expert on intoxication related offenses, the effects of intoxication on the body, standardized field
sobriety tests, and the standardized field sobriety course.        Sims objected, contending that
Sergeant Matthews was no more qualified than any other police officer as an expert on
intoxication. The trial court ruled that Sergeant Matthews could only testify as an expert on
intoxication related offenses and standardized field sobriety tests.
       The State requested an opportunity to lay an additional predicate for Sergeant Matthews’s
ability to testify as an expert on the effects of alcohol on the human body, and the trial court
consented. Sergeant Matthews testified that all of the courses he described dealt with the effects
of alcohol on the body and the outward appearances alcohol use manifests. He has instructed
others with regard to the effects of alcohol on the body and how alcohol is absorbed into the
body. He has had training on tolerance for alcohol and on homeostasis. Sergeant Matthews
testified that an entire chapter of his materials in the Drug Recognition Expert Program was
devoted to homeostasis and tolerance. Sergeant Matthews has fifteen years experience and has
dealt with at least 500 people who were under the influence of drugs or alcohol. He has
personally conducted ninety-three drug influence evaluations and has supervised others
performing evaluations. As part of the classes he has taught, volunteers drank alcohol so that the
students could observe the effects of alcohol and learn how to recognize them. Finally, Sergeant
Matthews testified that he has been able to compare his observations against an individual’s
tested blood alcohol level.
       The State then reoffered Sergeant Matthews as an expert on the effects of alcohol on the
body as well as on tolerance and homeostasis. Sims renewed his objection. The trial court
overruled that objection. Sergeant Matthews then testified that alcohol is a central nervous
system depressant that sometimes results in lethargy, such as droopy eyes, a tired appearance, or
rubbery legs. Even though a depressant, alcohol elevates a person’s pulse.           He described
homeostasis as the chemicals within the body and testified that, when a new chemical is
introduced, it changes the person’s homeostasis. He testified that over a period of time a person
can develop a tolerance to alcohol. A person with a tolerance for alcohol can eliminate alcohol
from their body faster and can appear unimpaired. Midland Police Officer Ernest Neil Truex

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testified that he administered an intoxilyzer test to Sims. Sims provided two samples. They
were measured at .164 and .147. Sergeant Matthews testified that a person with an alcohol
tolerance could register .164 on a breath test but look outwardly normal.
       The trial court’s decision on the admissibility of expert testimony is reviewed for an
abuse of discretion. Alvarado v. State, 912 S.W.2d 199, 216 (Tex. Crim. App. 1995). We will
uphold the trial court’s decision unless it lies outside the zone of reasonable disagreement.
Layton v. State, 280 S.W.3d 235, 240 (Tex. Crim. App. 2009). A trial court’s determination that
a witness is or is not qualified to testify as an expert is afforded great deference. Davis v. State,
313 S.W.3d 317, 350-51 (Tex. Crim. App. 2010). These rulings are rarely disturbed by appellate
courts. Vela v. State, 209 S.W.3d 128, 136 (Tex. Crim. App. 2006).
       Rule 702 provides that, “[i]f scientific, technical, or other specialized knowledge will
assist the trier of fact to understand the evidence or to determine a fact in issue, a witness
qualified as an expert by knowledge, skill, experience, training, or education may testify thereto
in the form of an opinion or otherwise.” TEX. R. EVID. 702. The evaluation of an expert’s
qualifications entails a two-step inquiry: first, a witness must first have a sufficient background
in a particular field, and second, the trial court must determine whether that background goes to
the very matter on which the witness is to give an opinion. Vela, 209 S.W.3d at 131. To be
qualified to give expert opinion testimony, the witness must possess some additional knowledge
or expertise beyond that possessed by the average person. Davis, 313 S.W.3d at 350.
       In Rodgers v. State, 205 S.W.3d 525, 528 (Tex. Crim. App. 2006), the Court of Criminal
Appeals outlined three criterion to be used in assessing whether a trial court has clearly abused
its discretion in ruling on an expert’s qualifications. These include: (1) whether the field of
expertise is complex; (2) how conclusive the expert’s opinion is; and (3) the centrality of the area
of expertise to the resolution of the lawsuit. In considering these criterion, “the appellate court
must review the trial court’s ruling in light of what was before that court at the time the ruling
was made.” Id. at 528-29.
       The effects alcohol has on a human body and whether an individual can develop a
tolerance to alcohol are not complex subjects. Homeostasis can potentially involve complex
areas of inquiry, but Sergeant Matthews did little more than define the term. Sergeant Matthews
did not render any conclusive opinions but provided only general information. Finally, his area
of expertise was not central to the resolution of the suit. The focus of the trial was Officer

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Truex’s observations and Sims’s intoxilyzer test results. Sergeant Matthews did not opine that
Sims was intoxicated or express any opinion on Officer Truex’s testimony.
         Sergeant Matthews has had considerable training and experience in the field of alcohol
detection. This is not to say that he would be qualified to render an opinion merely because it
touches upon alcohol and its effects on the body. There could, for example, be areas of inquiry
that require a medical expert; but Sergeant Matthews was not asked any such question. We note
that the trial court’s ruling was limited to whether Sergeant Matthews was an expert. The trial
court was not called upon to determine the extent of his expertise because there was no objection
to any of the State’s questions.1 The trial court did not abuse its discretion by finding that
Sergeant Matthews was an expert on the effects of alcohol and tolerance to alcohol. Issue One is
overruled.
         Sims’s second issue contends that he was harmed by the erroneous admission of
Sergeant Matthews’s testimony. Because we have found no error, it is unnecessary to address
this issue. The judgment of the trial court is affirmed.




                                                                   RICK STRANGE

                                                                   JUSTICE


October 21, 2010
Do not publish. See TEX. R. APP. P. 47.2(b).
Panel consists of: Wright, C.J.,
McCall, J., and Strange, J.




          1
            Sims did object to a subsequent question asking if there was a correlation between exhibiting six clues on the HGN
test and a blood alcohol level above .08. The trial court ruled that Sergeant Matthews could answer that question but that he
could not opine on Sims’s specific blood alcohol level.

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