Montana Code Annotated 2023

TITLE 61. MOTOR VEHICLES

CHAPTER 8. TRAFFIC REGULATION

Part 10. Driving Under Influence of Alcohol or Drugs

Evidence Admissible -- Conditions Of Admissibility

61-8-1018. Evidence admissible -- conditions of admissibility. (1) Upon the trial of a criminal action or other proceeding arising out of acts alleged to have been committed by a person in violation of driving under the influence, including 61-8-1002, an offense that meets the definition of aggravated driving under the influence in 61-8-1001, a similar offense under previous laws of this state or the laws of another state, or 61-8-805:

(a) evidence of any measured amount or detected presence of alcohol, drugs, or a combination of alcohol and drugs in the person at the time of a test, as shown by an analysis of the person's blood, breath, or oral fluid is admissible. A positive test result does not, in itself, prove that the person was under the influence of a drug or drugs at the time the person was in control of a vehicle. A person may not be convicted of a violation of 61-8-1002(1)(a) based on the presence of a drug or drugs in the person unless some other competent evidence exists that tends to establish that the person was under the influence of a drug or drugs while driving or in actual physical control of a motor vehicle within this state.

(b) a report of the facts and results of one or more tests of a person's blood, breath, or oral fluid is admissible in evidence if:

(i) a breath test, oral fluid screening test, or preliminary alcohol screening test was performed by a person certified by the forensic sciences division of the department to administer the test; or

(ii) a blood sample was analyzed in a laboratory operated or certified by the department or in a laboratory exempt from certification under the rules of the department and the blood was withdrawn from the person by a person competent to do so under 61-8-1019(1); and

(c) a report of the facts and results of a physical, psychomotor, or physiological assessment of a person is admissible in evidence if it was made by a person trained by the department or by a person who has received training recognized by the department.

(2) If the person under arrest refused to submit to one or more tests under 61-8-1016, whether or not a sample was subsequently collected for any purpose, proof of refusal is admissible in any criminal action or proceeding arising out of acts alleged to have been committed while the person was driving or in actual physical control of a vehicle upon the ways of this state open to the public while under the influence of alcohol, drugs, or a combination of alcohol and drugs. The trier of fact may infer from the refusal that the person was under the influence. The inference is rebuttable.

(3) The provisions of this part do not limit the introduction of any other competent evidence bearing on the question of whether the person was under the influence of alcohol, drugs, or a combination of alcohol and drugs.

History: En. Sec. 10, Ch. 498, L. 2021; amd. Sec. 4, Ch. 151, L. 2023.