§ 342.050. Chemical Tests, Results Admitted Into Evidence, When, Effect of.

A. 

Upon the trial of any person for violation of any of the provisions of Section 565.024, RSMo., or Section 565.060, RSMo., or Section 342.010 or 342.020 or upon the trial of any criminal action or violations of county or municipal ordinances or in any license suspension or revocation proceeding pursuant to the provisions of Chapter 302, RSMo., arising out of acts alleged to have been committed by any person while driving a motor vehicle while in an intoxicated condition, the amount of alcohol in the person's blood at the time of the act alleged as shown by any chemical analysis of the person's blood, breath, saliva or urine is admissible in evidence and the provisions of Subdivision (5) of Section 491.060, RSMo., shall not prevent the admissibility or introduction of such evidence if otherwise admissible. If there were ten-hundredths of one percent (0.10%) or more by weight of alcohol in the person's blood, this shall be prima facie evidence that the person was intoxicated at the time the specimen was taken.

B. 

Percent by weight of alcohol in the blood shall be based upon grams of alcohol per one hundred (100) milliliters of blood or grams of alcohol per two hundred ten (210) liters of breath.

C. 

The foregoing provisions of this Section shall not be construed as limiting the introduction of any other competent evidence bearing upon the question whether the person was intoxicated.

D. 

A chemical analysis of a person's breath, blood, saliva or urine, in order to give rise to the presumption or to have the effect provided for in Subsection (A) of this Section, shall have been performed as provided in Sections 577.020 to 577.041, RSMo., and in accordance with methods and standards approved by the State Department of Health.

E. 

Any charge alleging a violation of Section 342.010 or 342.020, or any County or municipal ordinance prohibiting driving while intoxicated or driving under the influence of alcohol shall be dismissed with prejudice if a chemical analysis of the defendant's breath, blood, saliva, or urine performed in accordance with Sections 577.020 to 577.041, RSMo., and rules promulgated thereunder by the State Department of Health demonstrate that there was less than ten-hundredths of one percent (0.10%) of alcohol in the defendant's blood unless one (1) or more of the following considerations cause the court to find a dismissal unwarranted:

1. 

There is evidence that the chemical analysis is unreliable as evidence of the defendant's intoxication at the time of the alleged violation due to the lapse of time between the alleged violation and the obtaining of the specimen;

2. 

There is evidence that the defendant was under the influence of a controlled substance, or drug, or a combination of either or both with or without alcohol; or

3. 

There is substantial evidence of intoxication from physical observations of witnesses or admissions of the defendant.