Whole Blood vs. Plasma in DWI Cases

Plasma vs. whole blood had been an area of conflict in the State of Texas for some time. It seemed for a while that the matter had been settled because in 2008, the Criminal Court of Appeals of Texas held that the definition of “blood” in the Penal Code meant “whole blood” and not plasma. Bigon v. State, 252 S.W.3d 360, 368 (Tex. Crim. App. 2008).

But a very recent case, Navarro v. State, brought the issue back to the forefront.

In Navarro, Joel Navarro was involved in an accident that injured his fiancée. Navarro v. State, 2015 WL 3424594 *1. (Tex. Ct. App. – Houston [14^th], May 28, 2015, WEST). Subsequently, the Defendant was charged with a DWI with a BAC of at least .15, which makes it a Class A Misdemeanor. Id. at *2.

The prosecutor’s instructed the jury that the Texas Penal Code does not define “blood” as whole blood or plasma. Id. at *3. He then requested the jury to include blood plasma in its determination of Mr. Navarro’s BAC. Id. The defense attorney subsequently objected, stating that plasma is inadmissible and the court must use whole blood, but the court overruled it and allowed the jury to use the plasma as evidence. Id.

In the subsequent appeal, the Houston Court of Appeals discussed how to define “blood” and whether it was proper to allow the jury to use plasma in its determination of Mr. Navarro’s guilt. The Court used dictionaries, medical texts and statutes to aide in their support their conclusion that blood was the “whole blood” and did not include subparts such as plasma. The dictionaries supported the idea that plasma was a subpart and in and of itself was not “blood”. Id. at *7. The statute the court used basically distinguished between “whole blood” and “plasma”. Id. The court found that this distinction meant that the legislature did not intend to include plasma as blood in its definition of the term. Id.

Because of this case, it would seem that once again the issue has been resolved once again. One can only hope that it is now clear to courts and prosecutors alike that whole blood must be used in DWI cases to determine blood alcohol concentration, not plasma.

Good defense attorneys should be equally on notice that whole blood is what the prosecution should be using and not plasma, or any other blood subpart. If the prosecution attempts to use it, the defense should be prepared and act quickly to strike or suppress that evidence based on Bigon and now Navarro in order to properly protect their client’s interests.