A first DWI conviction is normally punished as a Class B misdemeanor in Texas. Where a driver has provided a breath, blood, or urine sample that the state claims shows a blood alcohol content (BAC) of 0.15 or greater, the offense can become a Class A misdemeanor under Section 49.04(d) of the Texas Penal Code.
DRIVING WHILE INTOXICATED
(a) A person commits an offense if the person is intoxicated while operating a motor vehicle in a public place.
(b) Except as provided by Subsections (c) and (d) and Section 49.09, an offense under this section is a Class B misdemeanor, with a minimum term of confinement of 72 hours.
(c) If it is shown on the trial of an offense under this section that at the time of the offense the person operating the motor vehicle had an open container of alcohol in the person’s immediate possession, the offense is a Class B misdemeanor, with a minimum term of confinement of six days.
(d) If it is shown on the trial of an offense under this section that an analysis of a specimen of the person’s blood, breath, or urine showed an alcohol concentration level of 0.15 or more at the time the analysis was performed, the offense is a Class A misdemeanor.