DeLarue v. State
In DeLarue v. State, 102 S.W.3d 388, 400-02 (Tex. App.--Houston 14th Dist. 2003, pet. ref'd), the reliability of the State's evidence pertaining to the presence of marijuana in DeLarue's system at the time of the accident in question was at issue.
The court noted that the failure to extrapolate a controlled substance to the time of the accident could render the evidence insufficient under a Rule 403 analysis. Id. at 401.
The court further explained that "no attempt was made to quantify the presence; no attempt was made to show when the marijuana was introduced into his system; no attempt was made to show appellant was 'under the influence' of the marijuana at the time of the accident; and no attempt was made to show causation between appellant's behavior and the presence of marijuana in his system." Id.