Trace Amphetamine, Unquantified Methamphetamine, and the Problem of “Visible Impairment” in Michigan OWVI Cases
I often see drunk driving cases where the courtroom story begins as one thing and ends as something else. A case starts as an alcohol case because someone smells alcohol, because a driver admits drinking, or because the police investigation is framed around alcohol. Then the breath or blood test does not support the original theory. At that point, the case may shift. Alcohol becomes less important, prescription medication becomes a possibility, and a trace drug result becomes the centerpiece of the prosecution’s theory. That is why People v Highland is worth careful attention.
Highland is an unpublished Michigan Court of Appeals decision, so it is not binding precedent in the way a published opinion would be. Still, it illustrates a recurring problem in Michigan OWI and OWVI litigation: the difference between detecting a substance and proving that the substance impaired driving. Those are not the same thing. A laboratory may report that a compound was detected. A jury may hear that the compound is a controlled substance. But the legal question in an operating while visibly impaired case is not merely whether a substance was present. The question is whether the person’s ability to operate the vehicle was visibly impaired due to the consumption of alcohol, a controlled substance, another intoxicating substance, or a combination of those substances. MCL 257.625(3).
The facts in Highland were unusual but not unfamiliar. A citizen found the defendant slumped over the steering wheel of a pickup truck parked in the middle of the road. The citizen could not wake him at first and called police because he thought the defendant might be dead. When the defendant woke briefly, he reportedly said that he had been drinking, then nodded back out. Officers later observed that he was groggy, had droopy eyelids and thick slurred speech, and appeared unable to follow basic directions. He performed poorly, or could not complete, field sobriety testing. His preliminary breath test result was 0.019, and a later blood test detected no alcohol.
That is where the case changed. Once the alcohol evidence became weak, the prosecution relied on the theory that the defendant’s impairment was due to a controlled substance or other intoxicating substance. The Court of Appeals described the blood-test evidence this way: “Defendant’s blood samples were tested for alcohol and controlled substances but not prescription medication.” The same paragraph then stated that the test detected amphetamine at “less than ten nanograms per milliliter” and indicated the presence of an unquantified level of methamphetamine. People v Highland, unpublished per curiam opinion of the Court of Appeals, issued April 15, 2026 (Docket No. 370378).
That phrasing deserves scrutiny. Amphetamine is both a Schedule II controlled substance under Michigan law and a medication that may be lawfully prescribed. The categories are not mutually exclusive. A substance can be a controlled substance and also a prescription medication. The practical problem is that a jury may hear “controlled substance” and infer illegal drug use, abuse, or impairment, even when the actual toxicology finding is trace-level and when the record does not establish that the concentration was capable of explaining the observed behavior.
The amount matters. In Highland, the reported amphetamine concentration was not 100 ng/mL, 250 ng/mL, or some clearly quantified level. It was described as “less than ten nanograms per milliliter.” In the MSP toxicology format, that type of result would typically appear as a detected, quantified result reported below a threshold, such as amphetamine < 10 ng/mL. That notation should immediately raise a forensic question: if the result is below the lowest calibration level used for quantification, what exactly has been proved?
The MSP Toxicology Unit protocol language provided for this article states that, for LC-MS/MS Drugs of Abuse confirmatory analysis in blood, amphetamine calibration levels were validated at 10, 60, 120, 180, 240, and 300 ng/mL. If the lowest calibration level is 10 ng/mL, then a reported result of less than 10 ng/mL falls below the lowest calibration point. That does not necessarily mean that nothing was detected. It does mean that the reported value is at the lower edge of the method’s performance and should not be treated casually as a meaningful impairment concentration.
The controls matter as well. The same protocol material identifies amphetamine control concentrations at 20 ng/mL for the low control, 100 ng/mL for the medium control, and 250 ng/mL for the high control. A low control at 20 ng/mL does not directly validate reliable quantification at every concentration below 10 ng/mL. When a forensic laboratory reports a trace result, the defense should examine the validation study, calibration model, control data, chromatograms, ion ratios, retention time, signal-to-noise criteria, uncertainty information, and the laboratory’s reporting rules. Without that foundation, the legal system risks treating a trace analytical event as if it were proof of pharmacological effect.
The distinction between limit of detection and limit of quantification is central. The limit of detection is concerned with whether a method can reliably distinguish an analyte from a blank or background noise. The limit of quantification is concerned with whether the method can reliably measure the amount. Those are different scientific claims. A laboratory may be able to detect something at a very low level without being able to quantify it with the reliability needed to support a meaningful impairment opinion. According to the protocol language provided, the MSP Toxicology Unit listed an amphetamine LOD of 3.375 ng/mL and a lower reporting limit of 5 ng/mL. But a reported value below the lowest calibration level still invites serious cross-examination about what the result can and cannot prove.
Methamphetamine created an additional problem. The Court described the methamphetamine as present at an “unquantified level.” That is not the same as a measured concentration. An unquantified finding may have investigative significance, but it is far weaker as impairment evidence. If the prosecution cannot tell the jury how much methamphetamine was present, the prosecution’s ability to connect that finding to driving ability becomes more difficult. Presence is not impairment. A drug name is not a dose. A dose is not necessarily an impairing dose. And even an impairing dose must still be connected to the defendant’s condition at the relevant time.
The defense toxicologist in Highland, Dr. Randall Commissaris, focused on concentration. He testified that drug concentration was the primary factor in determining whether a substance affects driving ability. He also explained that methamphetamine and amphetamine are central nervous system stimulants and would not cause drowsiness or sleepiness. That testimony mattered because the most striking observations in the case involved the defendant being asleep, groggy, nodding off, and difficult to rouse. If the prosecution theory is stimulant impairment, but the observed behavior is dominated by sedation or sleepiness, a careful defense lawyer should press the mismatch.
The Court of Appeals nevertheless affirmed the conviction. That result is important to understand because the appellate issue was sufficiency of the evidence, not whether the trial court should have excluded the toxicology evidence after a fully developed evidentiary challenge. Sufficiency review is deferential. The reviewing court looks at the evidence in the light most favorable to the prosecution and asks whether a rational trier of fact could find the essential elements beyond a reasonable doubt. The Court relied on the observations of the defendant’s condition, the body-camera evidence, the field sobriety evidence, the toxicology findings, and the rule that jurors may believe or disbelieve expert testimony in whole or in part.
That appellate posture limits what Highland actually proves. The opinion does not establish that trace amphetamine below 10 ng/mL is scientifically meaningful impairment evidence in every case. It does not establish that an unquantified methamphetamine result reliably proves impairment. It does not eliminate the need for a proper foundation under the Michigan Rules of Evidence. It does not prevent a defense lawyer from challenging whether the toxicology evidence is relevant, whether it is unfairly prejudicial, whether the expert opinion is reliably supported, or whether the prosecution can connect the analytical result to the defendant’s driving ability.
This distinction is critical. A sufficiency appeal after conviction is often a difficult vehicle for attacking weak forensic science. By that stage, the evidence has already been admitted, the jury has already heard it, and the appellate court gives substantial respect to the jury’s role. The better litigation question is often presented earlier, through discovery, motion practice, expert consultation, and a focused evidentiary challenge. In a trace-drug OWVI case, the defense should not wait until trial to learn whether the laboratory can explain its calibration range, its reporting threshold, its uncertainty, its validation studies, and its basis for distinguishing a trace finding from analytical noise.
There is also a statutory precision issue. MCL 257.625(3) requires visible impairment due to the consumption of a qualifying substance. The Court in Highland correctly recognized that amphetamine and methamphetamine are controlled substances under Michigan law. But the fact that a substance is listed as controlled does not answer the causation question. The prosecution still must prove that consumption weakened or reduced the defendant’s ability to drive such that the defendant drove with less ability than an ordinary, careful, and prudent driver. In a trace-level case, that causal link is where the real litigation should occur.
For lawyers, Highland is a reminder to separate three questions that often get blurred. First, was a substance detected? Second, was it reliably quantified at a concentration that can be interpreted? Third, did the substance cause visible impairment of the ability to operate a motor vehicle? The prosecution may have evidence on the first question and still have a weak case on the second or third. The defense should insist that each question be answered separately.
For clients, the lesson is more practical. A blood test that says “detected” does not automatically mean that the case is over. A trace result may be scientifically complicated. A prescription medication may also be a controlled substance. A field sobriety test may be affected by fatigue, weather, medical conditions, age, balance issues, footwear, anxiety, or the conditions under which the test was administered. A person found asleep in a vehicle may present a serious legal problem, but the prosecution still has to prove the elements of the charge with admissible and reliable evidence.
My concern with Highland is not that the Court applied the wrong sufficiency standard. The Court applied a deferential standard that gives the prosecution the benefit of reasonable inferences after a jury verdict. My concern is that trace toxicology can sound far more powerful than it is. When a juror hears “methamphetamine” or “amphetamine,” the word itself can carry weight beyond the science. That is why the defense must translate the laboratory result into its proper forensic meaning. Less than 10 ng/mL is not a dramatic drug level. An unquantified result is not a pharmacological explanation. A laboratory detection is not the same as impaired driving.
The strongest defense approach in a case like this is disciplined and technical. Obtain the toxicology packet. Review the chromatograms. Identify the calibration range. Compare the reported value to the lowest calibrator and the low control. Determine whether the laboratory’s method was validated for the reported interpretation. Examine whether the analyst is offering only a detection opinion or whether the prosecution is trying to turn that detection into an impairment opinion. Then compare the claimed drug effect to the actual observations in the video and police reports.
Highland should not be read as a broad endorsement of trace-drug prosecutions. It should be read as a warning. Once trace toxicology evidence reaches a jury, an appellate sufficiency challenge may be an uphill battle. The more effective work often occurs before trial, when the defense can challenge the foundation, limit the interpretation, educate the court, and prevent a scientifically weak result from being given more legal significance than it deserves.
I look at these issues carefully because a drunk driving case is rarely just about one number, one test, or one police report. The legal question is whether the evidence was obtained, interpreted, and presented in a way that Michigan law permits. In trace-drug OWVI cases, that question requires more than asking whether a substance was detected. It requires asking whether the science can support the conclusion the prosecution wants the jury to draw.
