Drunk driving charges are pursued by prosecutors through the presentation of evidence to support legal claims. In Texas, a variety of different sources of evidence may be used to show that a driver was allegedly intoxicated while operating their vehicle. The results of field sobriety tests may be offered as well as testimony from law enforcement officers who allegedly witnessed the defendant’s allegedly suspicious conduct.

Another source of evidence that may be offered during a DWI trial is the results of a blood alcohol concentration (BAC) test. A BAC test is a scientific assessment of how much alcohol is in one’s blood and therefore their body at the time of their test. The human body processes alcohol out of the blood at about one drink per hour and if the concentration of alcohol in the system shows more than .08% then the individual may be considered too intoxicated to drive.

Texas follows a “per se” intoxication law for DWI which means that even if a person is not exhibiting other signs or symptoms of drunkenness, if their BAC is at .08% they will be considered too intoxicated to drive. Individuals under the age of 21 who have BAC results of at least .02% are also considered too drunk to drive under the state’s zero tolerance law.

Blood alcohol concentration tests are far from perfect and individuals should know that many factors can influence the alleged concentration of alcohol in their bodies. A person’s body type, gender, metabolism, and even time can factor into whether their BAC test is completely accurate.

Overcoming evidence to disprove a claim of DWI can be challenging and can require careful defense strategy planning. Individuals who are worried about what DWI convictions may do to their lives can get help. Criminal defense lawyers who offer DWI defense services can be excellent resources for those with questions and concerns.