Chemical breath tests have recently come under increased scrutiny from the public because of mistakes and errors they produce. Compared with the potential for false positives or wholly inaccurate results during chemical breath testing, blood tests may present a better option for law enforcement in Texas.
If officers pull you over because they suspect you are driving while intoxicated (DWI), they will ask you to perform a chemical breath test and a field sobriety test. If you fail those tests or if you refuse the chemical breath test, officers may attempt to draw blood in order to establish the presence of alcohol in your system. When do you have to allow the state to draw your blood in Texas?
If you give consent
The simplest way for officers to get a blood sample from a person allegedly involved in an impaired driving offense involves getting permission from that person. Some individuals will readily consent to a blood test because they know the breath test was inaccurate and a blood test will exonerate them. Others, possibly including those already under the influence, may not consider the consequences when they give their permission.
If you cause a crash that kills someone
In the event that someone whom officers believe drove while under the influence causes a crash that kills someone, officers can demand a blood draw. It’s important to note that regardless of the circumstances that lead to a chemical blood test, police officers themselves will not be the ones that perform the blood draw. A medical professional with proper training will do so. However, officers may assist in restraining an individual accused of impaired driving in order to facilitate a blood draw in some cases.
If the officers can secure a warrant quickly enough
Your blood alcohol concentration (BAC) may change dramatically in the hours after an arrest. Those who had several drinks right before getting behind the wheel might experience increased intoxication, while others may experience a notable drop in BAC.
Officers have a very small window of time in which they can gather blood evidence to use to prove impairment. Provided that they can secure a warrant from a judge during that window of time, officers can compel an individual to submit to a blood draw regardless of consent.