The evidence in a Michigan OWI case

An OWI case in Michigan is built from several kinds of evidence: what the officer saw, field sobriety tests, a roadside breath test, an evidential breath, blood or urine test, video, and the driver's own statements. Each kind has its own rules about when it can be used. The chemical-testing provisions of MCL 257.625a "do not limit the introduction of any other admissible evidence" on the questions in the case.^[8]

This page sets out each category and the rules that govern it. It does not assess the strength of any particular piece of evidence. For how a jury is told to weigh the evidence, see jury trials.

Evidence at a glance

Evidence	Main rule
Officer observations of driving and condition	Jurors may consider reflexes, vision, walking, talking, manner of driving and judgment[9]
Standardized field sobriety tests	Qualified witness may testify on a proper foundation[6]
Roadside PBT result	Three limited uses only[3]
Evidential breath, blood or urine result	Admissible; presumed the same as at the time of driving[1]
Refusal of the chemical test	Only to show a test was offered[5]
Driver's statements	Subject to Miranda and the corpus delicti rule[10][11]
Expert opinion	MRE 702 relevance and reliability[7]

Officer observations

For OWI, the jury decides whether the defendant operated a vehicle, in a place open to the public or generally accessible to vehicles, while under the influence or with an unlawful alcohol content.^[12] Jurors are told that "under the influence" means the ability to drive was "substantially lessened," and that drinking or smelling of alcohol alone does not prove it.^[13] They may consider the defendant's condition when driving, including reflexes, vision, walking, talking, manner of driving and judgment.^[9] On request, the prosecution must provide any police report concerning the case.^[14]

Field sobriety tests

MCL 257.625s provides that a person "qualified by knowledge, skill, experience, training, or education, in the administration of standardized field sobriety tests, including the horizontal gaze nystagmus (HGN) test, shall be allowed to testify subject to showing of a proper foundation of qualifications."^[6] The same section does not prevent a nonstandardized test from coming in if it complies with the Michigan Rules of Evidence.^[6] In Peebles, an officer with four or five hours of training on the tests plus on-the-job training was found qualified.^[15] The federal training manual describes the tests as "a tool to assist you in seeing visible signs of impairment" and "not a pass/fail test."^[16] See field sobriety tests.

The roadside breath test (PBT)

PBT results are admissible in an OWI prosecution only to help decide a challenge to the validity of an arrest, and for the other limited purposes listed in MCL 257.625a(2)(b), which include rebutting certain testimony about the defendant's alcohol level at the time of the offense.^[3][4] The Court of Appeals held in Parrott that the limit is constitutional and that "neither may use PBT results unless the result rebuts certain testimony regarding the defendant's BAC at the time of the offense."^[4] A PBT may be given only after the operator determines the person has not smoked, regurgitated or put anything in the mouth for at least 15 minutes.^[17] See the preliminary breath test.

Evidential breath, blood and urine tests

Under MCL 257.625a(6)(a), the alcohol or drug level shown by chemical analysis "is admissible into evidence in any civil or criminal proceeding and is presumed to be the same as at the time the person operated the vehicle."^[1] The jury instruction softens this: jurors "may infer" the level was the same, may consider evidence of drinking after driving, and "may give the test whatever weight" they believe it deserves.^[2] Jurors are also asked whether the test was technically accurate, the equipment properly maintained, the test given correctly and the operator properly trained.^[18]

Breath tests

Michigan's evidential breath instrument is the Intoxilyzer 9000, which replaced the DataMaster DMT.^[19][20] The State Police rules require:

• observation by a certified operator for at least 15 minutes before the sample;^[21]
• accuracy within plus or minus 5% using a controlled device;^[22]
• two samples, with the first legally sufficient and the second confirming it, within set tolerances;^[23][24]
• a third sample if the first two do not agree, and then a request for blood or urine if the third does not conform.^[25]

The Court of Appeals has addressed the observation rule in more than one case: Boughner involved an operator who observed the defendant "for no more than eight minutes," while Wujkowski found "only a de minimis, technical violation" in a six-second break.^[26] See challenging breath test results.

Blood and urine tests

Only a licensed physician, or a qualified person under a physician's delegation acting in a medical environment, may draw blood at an officer's request.^[27] The rules bar alcohol swabs and require that collection be witnessed, each sample labeled, and samples sent to a lab sealed to ensure integrity.^[28] Lab calibration must be checked with control samples each day tests are run, with control results kept at least 1 year.^[29] Blood drawn after a crash for medical treatment is admissible "regardless of whether the person had been offered or had refused a chemical test."^[30] See blood tests in OWI cases.

Getting the results before trial

On a written request, the prosecution must provide test results at least 2 days before trial, and failure to fully comply "bars the admission of the results into evidence by the prosecution."^[31] A forensic lab report served on the defense can come in without the analyst unless the defense files a written objection within 14 days of receiving notice.^[32]

Refusing the chemical test

MCL 257.625a(9) makes a refusal admissible "only to show that a test was offered to the defendant, but not as evidence in determining the defendant's innocence or guilt," and requires that the jury be instructed accordingly.^[5] The instruction, M Crim JI 15.8, tells jurors that the evidence "is not evidence of guilt."^[33] See refusal evidence at trial.

The driver's statements

• Miranda. A person subjected to custodial interrogation is entitled to Miranda safeguards "regardless of the nature or severity of the offense," including traffic misdemeanors.^[10] A motorist detained for a routine traffic stop "is ordinarily not in custody within the meaning of Miranda."^[34]
• Corpus delicti. A confession may not be admitted unless independent evidence shows the injury occurred and that criminal agency caused it; the rule is confined to confessions.^[11]
• Voluntariness. A challenge to a confession is decided at a Walker hearing outside the jury, and the prosecution bears the burden of showing admissibility.^[35]

See Miranda rights and OWI stops.

Video evidence

Police must keep evidentiary body-camera recordings at least 30 days, and recordings tied to an ongoing criminal investigation or prosecution until it ends.^[36] The statute "does not create a presumption" that a missing recording would corroborate either side.^[37] In Jones, the Court of Appeals held that, absent intentional suppression or bad faith, a loss of evidence before a defense request does not require reversal.^[38] The discovery guide explains how to request video.

Expert testimony

Under MRE 702, a qualified expert may testify if the proponent shows the court it is more likely than not that the testimony will help the jury and rests on sufficient facts or data, and the court "acts as a gatekeeper" to ensure the testimony is relevant and reliable.^[7] In Bowden, the Court of Appeals held that the prosecution failed to establish the reliability of a drug recognition expert's opinion on the degree of marijuana impairment.^[39]

Evidence obtained through an unlawful stop, arrest or search may be challenged before trial in a motion to suppress.^[40]