In Alabama, a person is guilty of a DUI if he or she (1) operates a motor vehicle while under the influence of a controlled substance to a degree which renders him or her incapable of driving safely, OR (2) operates a motor vehicle under the combined influence of alcohol and a controlled substance to a degree which renders him or her incapable of driving safely. Ala. Code Ann. §§ 32-5a-191(a)(3)-(4) (West 2010).
The fact that any person charged with DUI is legally entitled to use a controlled substance does not constitute a defense against any charge of violating this section. Id. § 32-5a-191(d).
In Alabama, a person suspected of driving while under the influence of alcohol has, by virtue of driving in the state, consented to provide a sample of breath, blood or urine to police for testing in order to determine the amount of alcohol in his or her system. However, implied consent law does not require that an individual suspected of driving under the influence of marijuana or controlled substance submit to a chemical test in order to screen for the presence of drugs in his or her body. Ergo, in Alabama a chemical sample from an accused person should only be given on a voluntarily basis, and no penalties or sanctions apply for refusal to submit to chemical testing for drugs.
An exception applies if a motorist is involved in an accident that causes serious physical injury. In such a case, state can take blood sample to test for cannabis impairment. Id. § 32-5A-192.1(a).
Alabama allows law enforcement officials to conduct roadblocks under the Federal Constitution.
Leu v. City of Mountain Brook, 386 So.2d 483 (Ala.Crim.App.1980) – Driving after ingesting a drug which renders driver incapable of safely driving is a violation of state law.
Raper v. State, 584 So.2d 544 (Ala.Crim.App.1991) – To convict, the prosecution must prove that defendant was under the influence of a substance to the extent that it affected his or her ability to operate the vehicle in a safe manner.
Lunceford v. City of Northport, 555 So.2d 246 (Ala.Crim.App.1988) -- Implied consent law does not apply on private property. Production of a breath sample is voluntary on private property.
Krumm v. City of Robertsdale, 648 So.2d 651 (Ala.Crim.App.1994) – Evidence that defendant was in possession of marihuana was inadmissible. Defendant was charged with driving under the influence of alcohol, not driving under the influence of both alcohol and a controlled substance. Probative value evidence of possession did not outweigh its potential prejudicial effect.