Dallas Criminal Lawyer

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. Namely that the sample was take

  • At the request or order of a peace officer under this chapter
  • By a physician, qualified technician, chemist, registered professional nurse, or  licensed vocational nurse;
  • In a sanitary place.

The statue specifically states that emergency medical service personnel do not qualify as qualified technicians, so ambulance personnel cannot take the sample.

Compelling A Blood Sample  

The circumstances under which a person can be compelled against their wishes to give a specimen of their blood are set out in Transportation Code Section 7214.012.


One or more specimens of a person’s breath or blood may be taken if the person is arrested and at the request of a peace officer having reasonable grounds to believe the person:

  • while intoxicated was operating a motor vehicle in a public place, or a watercraft;  or
  • was in violation of Section 106.041, Alcoholic Beverage Code.

A peace officer shall require the taking of a specimen of the person’s breath or blood if:

  • the officer arrests the person for an offense under Chapter 49, Penal Code, involving the operation of a motor vehicle or a watercraft;
  • the person was the operator of a motor vehicle or a watercraft involved in an accident that the officer reasonably believes occurred as a result of the offense;
  • at the time of the arrest the officer reasonably believes that as a direct result of the accident:
    • any individual has died or will die;  or
    • an individual other than the person has suffered serious bodily injury;  and
  • the person refuses the officer’s request to submit to the taking of a specimen voluntarily.
  • The peace officer shall designate the type of specimen to be taken.
  • In this section, “serious bodily injury” has the meaning assigned by Section 1.07, Penal Code.

The new category of cases in which an officer shall compel a specimen are as follow

  • Bodily Injury Bodily injury means physical pain, illness, or any impairment of physical condition.
  • Felony DWI Arrests If at the time of arrest, the officer possesses or receives information from a credible source that the suspect has twice before been convicted of DWI, the officer must take a blood sample.
  • DWI with Child Passenger In every case where an officer arrests a suspect for the offense of DWI with child passengers, now requires that the officer take a mandatory blood specimen.
  • Prior Intoxication Assault, Intoxication Manslaughter, DWI with Child Passenger Arrests If at the time of the arrest, the officer possess or receives  reliable information from a credible source that the suspect has previously been convicted of Prior Intoxication Assault, Intoxication Manslaughter, DWI with Child Passenger Arrests, the officer must take a mandatory blood specimen.

Blood Evidence

To admit blood evidence, 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 medial records to prove a blood test result.  It isn’t necessary that the person who actually drew or tested the blood to testify.  An officer’s testimony that she witnesses the nurse draw the defendant’s blood will be sufficient.

The Blood Vial

The vial should have been stored in a refrigerator.  The longer the delay, the greater the defense attacks on the way the blood sample was preserved.  Look to see if the label was placed on the vial such that some portion of the top of the vial is covered.

Medical Samples

If the sample was drawn under standard medical procedures by the hospital to help diagnose or treat a person, that sample will be admissible if you show a proper chain of custody.  If law enforcement are not involved in the decision to draw the blood sample, the requirements of Transportation Code Section 724.012 are inapplicable, as are constitutional prohibitions against unreasonable search and seizures.


If the defendant consents to a blood draw, there is ample authority that he has waived the statuary requirements.  If the person is incapable of giving consent or refusing to give a sample, under the implied consent law, he will be deemed to have consented if he is unconscious, dead, or otherwise incapable of refusal, so long as he has been placed under arrest.

Exigent Circumstances

The fact  that alcohol in the blood will dissipate quickly, also will justify the taking of a blood specimen in non arrest situations.  In Aliff v. State, the defendant was seriously injured in a car crash that left another motorist dead.  After the defendant was transported to the hospital, the officer requested that a sample be drawn even though the defendant did not give his consent and was not under arrest at the time.  In upholding the taking and admission of the blood specimen, the court held that the statute requiring the consent of a suspect before blood is taken only applies to situations where there has been an arrest.  The court further held that taking the blood specimen did not violate the Fourth Amendment.  Even though officers had not actually arrested the defendant when his blood sample was taken, the court ruled the blog results were admissible because the officers had probable cause to arrest the suspect for involuntary manslaughter.

Blood Search Warrants

The state can use a search warrant to obtain a blood specimen.  The Court of Criminal Appeals has ruled that the existence of the implied consent law does not preclude law enforcement drawing a suspect’s blood under a search warrant.  A blood warrant is mere evidence warrant and must be signed by a judge from a court of record.

A search warrant issued  (to take the suspects blood is an evidentiary search warrant under CCP ar. 18.02.  As such, it has additional statutory requirements.  First, it must be signed by a magistrate in a court of record.  This requirement eliminates justices of the peace and most municipal court judges.  An exception exists for some very small counties.  THe affidavit must allege probable cause that a particular person committee an offense and that the evidence to be seized constitutes evidence of this crime.  The blood warrant also differs from the more common search warrant in that it must identify the  person to be searched instead of the location or place to be reached.


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.