People come to me bewildered after an amphetamine-related drunk driving arrest. Some have a valid prescription for Adderall or Ritalin. Others took a friend's pill before a long drive and never expected to end up in the back of a patrol car. A few are facing this charge because a low-level laboratory finding turned a routine stop into a controlled-substance case. Whatever the circumstances, the questions are the same: How can the State prove I was "under the influence" of amphetamine? Does any trace in my blood mean I am guilty? And what does the laboratory report really show? In my practice, the answers depend less on assumption than on a careful look at the statute, the science, and the report itself.
The Michigan Statutory Framework
Michigan's operating-while-intoxicated statute, MCL 257.625, treats drug-related driving offenses differently depending on the substance and the proof. Under MCL 257.625(1), it is unlawful to operate a vehicle on a highway or other place open to the general public or generally accessible to motor vehicles while "under the influence" of a controlled substance or other intoxicating substance. The Court of Appeals has explained that OWI under MCL 257.625(1) requires the prosecution to prove that the defendant operated a motor vehicle on a qualifying roadway "while under the influence of liquor or a controlled substance, or a combination of the two, or with [an unlawful bodily alcohol content]." People v Hyde, 285 Mich App 428, 447-448 (2009). The "under the influence" prong is interpreted through People v Lambert, 395 Mich 296 (1975), which described an "under the influence" driver as one whose ability to drive "was substantially and materially affected" by the substance consumed. Oxendine v Secretary of State, 237 Mich App 346, 353-354 (1999).
The lesser offense of operating while visibly impaired, MCL 257.625(3), prohibits operation when, due to a controlled substance, "the person's ability to operate the vehicle is visibly impaired." The Court of Appeals has held that this provision requires "evidence describing or depicting actions, conduct, characteristics, or movements of the person during the pertinent time period, revealing an impaired ability relevant to operating a vehicle." People v Mikulen, 324 Mich App 14, 17, 22-23 (2018). The focus is on whether "the person's capacity to drive was impaired as could be observed by another." Id. at 23.
Finally, MCL 257.625(8) creates Michigan's so-called "zero tolerance" drug offense, but only for controlled substances listed in schedule 1 under MCL 333.7212 or those described in MCL 333.7214(a)(iv). Cases like People v Koon, 494 Mich 1 (2013), People v Feezel, 486 Mich 184 (2010), and People v Stock, 507 Mich 1008 (2021), illustrate that prosecutors must identify the precise controlled substance the Legislature included within the scope of that subsection. When I evaluate an amphetamine case, I look first at whether the charging theory is "under the influence" under MCL 257.625(1), "visibly impaired" under MCL 257.625(3), or some combination — because the burden of proof shifts dramatically depending on which theory applies.
Why Mere Presence of Amphetamine Is Not Enough
I often have to explain to clients that a positive laboratory result alone does not establish OWI. The third element of MCL 257.625(1) is disjunctive and may be satisfied either by an unlawful bodily alcohol content or by proof that the driver was "under the influence" of a controlled substance. Hyde, 285 Mich App at 447-448. For amphetamine, there is no per se concentration threshold in MCL 257.625(1). The State must prove actual intoxication — that the defendant's ability to drive was "substantially and materially affected" — or, if the case proceeds on the lesser offense, that the impairment was visible to an ordinary, observant person. Oxendine, 237 Mich App at 354; Mikulen, 324 Mich App at 23.
This burden is significant because the peer-reviewed forensic literature does not support a clean dose-response relationship between blood amphetamine concentration and driving impairment. Musshoff and Madea reviewed thousands of amphetamine-positive driving cases and reported that "[r]elations between concentration and effect could not be established." Frank Musshoff & Burkhard Madea, Driving Under the Influence of Amphetamine-Like Drugs, 57 J Forensic Sci 413 (2012). Jones, Holmgren, and Kugelberg, examining roughly 15,898 amphetamine-positive blood samples from apprehended Swedish drivers between 2000 and 2004, similarly observed a "lack of association between the concentration of amphetamine in blood of DUID suspects and the signs and symptoms of drug influence noted from a clinical examination by a physician." Alan Wayne Jones, Anita Holmgren & Fredrik C. Kugelberg, Driving Under the Influence of Central Stimulant Amines, 69 J Stud Alcohol Drugs 202 (2008). The Norwegian impairment study by Gustavsen, Mørland, and Bramness reported only a modest concentration-effect relationship in suspected drugged drivers and found that any relationship "reached a ceiling at blood amphetamines concentrations of 0.27–0.53 mg/l," with younger drivers more often judged impaired than older drivers at the same concentration. Ingebjørg Gustavsen, Jørg Mørland & Jørgen G. Bramness, Impairment Related to Blood Amphetamine and/or Methamphetamine Concentrations in Suspected Drugged Drivers, 38 Accid Anal & Prev 490 (2006). The Silber group, after three placebo-controlled studies dosing volunteers with d,l-dexamphetamine, d,l-methamphetamine, or d-methamphetamine at 0.42 mg/kg, concluded that "[u]nder these conditions, the SFSTs are not a sensitive measure for detecting the presence of low levels of amphetamine." Beata Y. Silber et al., An Evaluation of the Sensitivity of the Standardised Field Sobriety Tests to Detect the Presence of Amphetamine, 182 Psychopharmacology 153 (2005).
In other words, the scientific record cautions against assuming that a positive amphetamine result, standing alone, proves the impairment that MCL 257.625(1) or MCL 257.625(3) requires. Therapeutic doses, as both the Drug Recognition Expert Pre-School Manual and the underlying pharmacology literature describe, may actually enhance attention and reaction time, while heavy use, the "come down" phase, and sleep deprivation produce a different impairment profile altogether.
The Laboratory Report — and What "Detected (quantified) amphetamine < 10 ng/mL" Really Means
The Michigan State Police Forensic Science Division Toxicology Unit confirms blood-amphetamine cases using liquid chromatography with tandem mass spectrometry, governed by procedure TX-PM 4.1.5 LC-MS/MS – Drugs of Abuse (LCDOA) Confirmatory Analysis in Blood, Document 8213, Revision 13, issued April 29, 2025. Section 4.1.5.11.1 defines the calibration levels for amphetamine as 10, 60, 120, 180, 240, and 300 ng/mL. Section 4.1.5.11.2 sets the low, medium, and high quality control concentrations at 20, 100, and 250 ng/mL. Section 4.1.5.11.3 reports a Limit of Detection of 3.375 ng/mL and a Lower Reporting Limit of 5 ng/mL.
A report that reads "Detected (quantified) amphetamine < 10 ng/mL" therefore describes a result below the laboratory's own lowest calibration standard. The protocol provides that analytes "present at a concentration <LOQ" but with an area ratio of analyte to internal standard at or above fifty percent of Standard 1 are reported as "< (LOQ)," and that values below that area-ratio threshold are considered negative for reporting purposes. Procedure 4.1.5.12. In my practice, I focus carefully on the difference between the Limit of Detection — the lowest concentration at which an analyte can be reliably distinguished from a blank or background noise — and the Limit of Quantification, the lowest concentration at which the laboratory will report a numeric value. When the laboratory's lowest quality-control material sits at 20 ng/mL, and its lowest calibration standard sits at 10 ng/mL, a stated LOD of 3.375 ng/mL without a corresponding uncertainty budget raises legitimate questions about whether the reported finding is forensically reliable for purposes of qualitative interpretation, much less for purposes of proving impairment.
Search, Seizure, and the Path to the Blood Sample
Long before the laboratory result becomes an issue, the Fourth Amendment governs how the State obtained the blood. A traffic stop is a seizure that must be supported by "an articulable and reasonable suspicion that a vehicle or one of its occupants is subject to seizure for a violation of law." Heien v North Carolina, 574 US 54, 60 (2014); Terry v Ohio, 392 US 1 (1968). Continued investigative detention to administer standardized field sobriety tests must rest on developing reasonable suspicion of impairment, and an arrest must be supported by probable cause. These categories are distinct, and I do not allow them to be blurred when I evaluate a case.
A nonconsensual blood draw is a search, Schmerber v California, 384 US 757, 770-771 (1966), and the natural metabolization of alcohol or drugs in the bloodstream is not a per se exigency, Missouri v McNeely, 569 US 141, 145 (2013). A motorist may not be deemed to have consented to a blood test "on pain of committing a criminal offense." Birchfield v North Dakota, 579 US 438, 476-478 (2016). Michigan's implied-consent statute, MCL 257.625c, supplies consent for chemical testing in qualifying arrests, but consent that is the product of misadvice, coercion, or unlawful detention is properly the subject of a motion to suppress. People v Stricklin, 327 Mich App 592 (2019).
Field Sobriety Testing, DREs, and Expert Reliability
Michigan recognizes the admissibility of standardized field sobriety tests through a qualified witness, "subject to showing of a proper foundation of qualifications." MCL 257.625s. But qualification is not the same thing as scientific reliability for a particular purpose. MRE 702, as amended effective January 1, 2004, requires the trial court to act as a gatekeeper and to confirm that the proponent has demonstrated that expert testimony is based on sufficient facts or data, is the product of reliable principles and methods, and reflects a reliable application of those principles to the facts of the case. Gilbert v DaimlerChrysler Corp, 470 Mich 749 (2004); People v Muniz, 343 Mich App 437 (2022); Daubert v Merrell Dow Pharmaceuticals, Inc, 509 US 579 (1993).
In People v Bowden, 334 Mich App 171 (2022), the Court of Appeals held that a Drug Recognition Expert's opinion that the defendant was driving while impaired by marijuana was not sufficiently reliable because the prosecution failed to validate the DRE protocol "as a reliable method of demonstrating a person's level of impairment due to marijuana or the degree to which a person's driving abilities could be diminished by any given level of marijuana." The reasoning matters for amphetamine cases. In my practice, I examine whether the State has presented any evidence that the DRE protocol — or the field sobriety battery, for that matter — has been validated as a reliable method of distinguishing low-level amphetamine presence from amphetamine impairment.
Where the Litigation Lives
Motion practice is where these cases are framed. A motion may preserve constitutional issues, define what an expert may say, or seek suppression of evidence obtained in violation of the Fourth Amendment. Discovery under MCR 6.201 should include the full laboratory bench notes, calibration records, control charts, instrument maintenance logs, and the analyst's training and proficiency records. When I evaluate a case, I read the chromatograms, the ion ratios, and the relative retention time calculations alongside the procedure manual to determine whether the result the State intends to introduce conforms to TX-PM 4.1.5 in fact, not just in caption.
I do not promise outcomes. Each case turns on its own facts: the driving conduct that justified the stop, the observations during the encounter, the administration of any sobriety testing, the consent or warrant supporting any blood draw, the chain of custody, the analytical record, and the precise charging theory the prosecutor selects. What I can say is that the law requires proof, the science requires rigor, and a low-level amphetamine finding does not in itself supply either.
Conclusion
An OWI charge premised on amphetamine demands more than a positive screen and a number on a lab report. It demands that the prosecution prove either that the driver's ability to operate the vehicle was substantially and materially affected — the OWI threshold of MCL 257.625(1) under Lambert and Hyde — or that the impairment was visible to an ordinary observer as MCL 257.625(3) requires under Mikulen and Oxendine. It demands that the search-and-seizure record satisfy the Fourth Amendment from the stop through the blood draw. And it demands that any expert opinion, whether from a field sobriety witness, a Drug Recognition Expert, or a forensic toxicologist, meet the reliability standard of MRE 702 as it has been applied in Bowden and Muniz. When those elements are tested carefully — and when the laboratory's own protocols, calibration design, and reporting conventions are read against the result — the picture in an amphetamine case is rarely as simple as the charging document suggests.
