When it comes to matters related to driving while intoxicated, Texas motorists do not have to worry about checkpoints, as they are illegal under most circumstances. However, the same cannot be said about reasonable suspicion.
Texas is one of about a dozen states where law enforcement agencies are generally not allowed to establish checkpoints solely for the purpose of checking for drivers who may be under the influence, but this does not hinder the ability of police officers to justify traffic stops for the purpose of investigating potential drunk driving situations.
Law enforcement officers have ample leeway to apply the principle of reasonable suspicion when they stop drivers. Anything that could be construed as erratic driving would justify a suspicion of a criminal violation. This may include changing lanes too slowly, seeing the brake lights come on too often, turning right on a red light without stopping, and many other reasons. Even a missing headlight or an expired registration can justify a traffic stop, which could later turn into a DWI charge if the officer claims to smell liquor or detect signs of impairment.
Depending on the circumstances of a DWI case, an attorney can focus on reasonable suspicion aspect for the purpose of improving the outcome of clients. In some cases, police officers handle traffic stops in an overzealous manner or even lie about their actions. Questioning the conduct of officers along with the reasons they formulate reasonable suspicion may convince prosecutors to lower or even dismiss the charges if they believe that the case could fall apart in court.
Source: FindLaw, “What is Reasonable Suspicion for a DUI Stop?“, Aug. 30, 2017