The Texas Transportation Code requires that before an officer can take a blood sample from the defendant suspected of an intoxication offense, three requirements must be met:
1. There is a life threatening incident;
2. The defendant was arrested for an intoxication offense under Chapter 49; and
3. The arresting officer "reasonably believed the accident occurred as a result of the offense".
Because reasonable belief is a separate requirement, it must be based on something more than the mere fact of an accident and an arrest for intoxication. This belief must be based on specific and articulable facts of causation and can result from a number of factors, including witness interviews, conclusions drawn from experience and combination with the observation of the accident scene, or determinations made by an accident reconstruction team.
If the state has a valid search warrant for a suspect's blood, it need not get the suspect's consent through the implied consent statute or otherwise.