Drug recognition experts (DREs) in Michigan drugged-driving cases

A drug recognition expert (DRE) is a police officer with specialized training in spotting impairment caused by drugs rather than, or in addition to, alcohol. Michigan's Vehicle Code defines a "certified drug recognition expert" as "a law enforcement officer trained to recognize impairment in a driver under the influence of a controlled substance rather than, or in addition to, alcohol."^[1]

This page covers the evaluation, what Michigan courts have said about DRE opinions, and how DREs fit into roadside drug testing. For the drug offenses themselves, see the drugged driving law guide.

Why DREs matter in Michigan drug cases

Michigan's OWI law can be violated by driving under the influence of a controlled substance or other intoxicating substance, and, separately, by driving with any amount of a Schedule 1 drug or cocaine in the body.^[5][6] The Vehicle Code sets no numeric THC limit, so marijuana cases are charged as "under the influence," visibly impaired, or any amount of a Schedule 1 substance.^[7] When an "under the influence" or visibly impaired charge is based on a drug, the jury (or the judge, on a plea or bench trial) generally must make a specific finding on whether the person was under the influence of or impaired by a drug, and the court reports it to the Secretary of State.^[8]

A DRE evaluation is a structured way for an officer to record observations in a suspected drug case. Whether an officer may give an expert opinion based on it is decided by the trial court, and jurors who hear an expert's opinion are told they do not have to believe it.^[3][9]

The 12-step DRE evaluation

A description of the protocol appears in People v Bowden (2022), where a certified DRE testified to 12 steps and 7 drug categories.^[2] The Court of Appeals summarized his testimony this way; it is a description of a witness's account, not a holding of the court.^[2]

1. A preliminary breath test.^[2]
2. An interview with the arresting officer.^[2]
3. A preliminary examination and first pulse check.^[2]
4. An eye examination.^[2]
5. Divided-attention tests.^[2]
6. Vital signs and a second pulse check.^[2]
7. Pupil sizes in different lighting conditions.^[2]
8. Muscle tone.^[2]
9. A check for injection sites and a third pulse check.^[2]
10. An interrogation.^[2]
11. The DRE's opinion, "based on the totality of the facts gathered in the previous 10 steps."^[2]
12. A laboratory toxicology report.^[2]

The 7 drug categories the witness listed are CNS depressants, CNS stimulants, hallucinogens, dissociative anesthetics, narcotic analgesics, inhalants and cannabis.^[2] The divided-attention and eye steps overlap with the roadside tests covered in the field sobriety tests guide and the HGN guide.

How many DREs Michigan has

In its March 2019 report, the Impaired Driving Safety Commission said: "There are only approximately 160 active DREs in Michigan at present; there are counties that do not have a DRE within their jurisdiction."^[10] The Commission recommended expanding DRE training.^[10] It also reported that about 20% of licensed Michigan officers had ARIDE training, an intermediate course between basic field sobriety training and DRE training.^[10]

The State Police report on Phase II of its roadside oral-fluid pilot (October 2019 to September 2020) said 131 DREs from 65 law enforcement agencies took part.^[11] These are dated figures from official reports; no current official DRE count was found for this guide.

Is DRE testimony admissible?

The court decides whether the officer is an expert

The Evidence Benchbook states: "Drug Recognition Evaluator or Expert (DRE) testimony is not automatically admissible, and the trial court must still make a determination whether a DRE officer is qualified to offer expert testimony."^[3] In Bowden, the Court of Appeals noted that even if a certification calls an officer a drug recognition "expert," "that label has no bearing on whether he may properly testify as an expert for purposes of MRE 702."^[12] MRE 702 is the Michigan Rule of Evidence on expert testimony.

What Bowden held

Bowden was an OWI prosecution based on marijuana use. The Court of Appeals reversed an order qualifying a DRE to testify that the defendant was impaired by marijuana to a degree that made driving unsafe.^[4] It held that "the prosecution failed to establish any valid connection between the use of the DRE protocol and a conclusion regarding the degree to which a person's driving ability was diminished by the use of marijuana," and so failed to meet its burden to show the testimony was reliable.^[4]

The Benchbook explains the court's reasoning. The studies the prosecution relied on showed the protocol's accuracy "with respect to determining whether a particular type of substance was present in a person's blood," but did not address "how particular levels of marijuana impacted a person's ability to drive."^[13] The court concluded that a DRE's determination that a person is impaired and unable to drive safely "appears to be ultimately based on the DRE officer's subjective judgment."^[13]

Reading Bowden carefully

• Bowden concerned a DRE opinion on the degree of marijuana impairment. It did not hold that DRE officers can never testify.^[4]
• The decision turned on the record before the court: the prosecution had not shown evidence that the protocol was validated for measuring the degree of marijuana impairment.^[4][13]
• Separately, MCL 257.625s allows a person qualified in giving standardized field sobriety tests to testify on a proper foundation of qualifications.^[14]

A common claim is that "DRE testimony proves drug impairment." In Bowden, the Court of Appeals held that the prosecution had the burden to establish the reliability, and thus the admissibility, of the proposed DRE expert testimony, and had not met it.^[4]

DREs and roadside saliva testing

Michigan's roadside oral-fluid statute is tied to DREs. Only a peace officer certified as a drug recognition expert, in a county participating in the State Police pilot program, may require a preliminary oral-fluid analysis.^[15] That officer needs reasonable cause to believe the person's ability to operate may have been affected by a controlled substance, or that the person had any amount of a Schedule 1 drug or cocaine in the body.^[15] Refusing a lawfully requested oral-fluid test is a civil infraction.^[16] The roadside saliva testing guide covers the pilot's history and legal status.

The toxicology step

The last step of the protocol is a laboratory toxicology report.^[2] The Michigan State Police Toxicology Unit tests blood and urine from law enforcement agencies in every county at its Lansing Laboratory.^[17] Lab results raise their own legal issues: for example, the Supreme Court held that the inactive THC metabolite 11-carboxy-THC is not a Schedule 1 substance, and in a later case reversed convictions where the evidence showed only an unidentified cocaine metabolite in the defendant's urine and did not support an inference that cocaine was in her body.^[18][19] See the THC blood tests guide and the drug-impaired driving evidence guide.

Prescription drugs

The protocol's drug categories, as described in Bowden, include narcotic analgesics and CNS depressants.^[2] Whether lawful use of a prescribed drug can still support an OWI charge is covered in the prescription drugs and OWI guide, and marijuana-specific rules are in the marijuana and driving law guide.