In Texas, a breath test or field sobriety test does not automatically prove you are guilty. The weight of the chemical test evidence is presumptive of alcohol influence, not conclusive. If there is no evidence to the contrary, the court may accept the legal presumption and conclude that the driver was or was not impaired on the basis of the chemical test alone. However, other evidence, such as testimony about the driver’s appearance, behavior or speech, for example, may be sufficient to overcome the presumptive weight of the chemical test. It is possible for a person whose Alcohol Concentration at the time of arrest is above the per se or presumptive level legal limit to be acquitted of DWI. It is also possible for a person whose Alcohol Concentration at the time is below the per se or presumptive level to be convicted of DWI. If the blood is drawn at the request of law enforcement, as opposed to a sample drawn at a hospital for medical purposes, the State must prove tat the provisions of Transportation Code Section 724.017 were followed.
To admit breath test results, the state must show:
- proper use of reference sample;
- existence of periodic supervision over the instrument and operation by one who understands the scientific theory of the instrument;
- proof of result of test by witnesses qualified to translate and interpret the result as to eliminate hearsay.
Testimony of an Intoxilyzer operator and technical supervisor that an instrument was periodically tested to make sure it was working properly; that a test sample run before the defendant’s Intoxilyzer tests demonstrated the machine was working properly; that the operator had been trained in the operation of the machine; and that the technical supervisor (who testified about the theory of the test) was certified by DPS, was sufficient preicate to admit the results of the Intoxilzyer test. The operator and technical supervisor each perform different function and will answer different questions.
To introduce blood results, the state must show:
- a proper chain of custody
- that the blood tested was the same as the blood drawn from the defendant.
The state cannot rely solely on medical records to prove a blood test result. However, it isn’t necessary that the person who actually drew or tested the blood testify. An officer’s testimony that she witnessed the nurse draw the defendant’s blood will be sufficient. The state need not show who drew the blood. Any objections to the stat’s failure to call the person who drew the blood, or any other gaps n the chain of custody, will go to the weight, but not the admissibility of the evidence.
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Dallas criminal lawyer Constantine Anagnostis dedicates his practice to people who are facing criminal charges, with a primary emphasis on DWI, Drug Offenses, Expunction & Nondisclosure Agreements, and Occupational Driver’s License Issues. Dallas criminal lawyer Constantine G. Anagnostis understands the law, procedures, and penalties pertaining to criminal law, and will aggressively fight to protect your rights. Dallas criminal lawyer Constantine Anagnostis provides the utmost personal dedication to each and every case, and truly cares about his clients. You may call 817-229-0319 to schedule a free consultation, or submit a sample case form. At the Law Office of Constantine G. Anagnostis, we look forward to helping you.