Background
John Henry Sliger was involved in an April 2020 collision with a dirt bike whose rider later died. After Sliger acknowledged drinking, he voluntarily took a portable breath test and, at an officer’s direction, spit out a lump of chewing tobacco. He was arrested and taken to jail, where he agreed to a Draeger breath test.
Before the jail test, Sliger denied having any foreign substance in his mouth, but Deputy Mitchell Kahns observed tiny tobacco strands between some of his teeth and did not remove them. The test showed an alcohol concentration above the legal limit, and the State charged Sliger with vehicular homicide. The trial court denied his motion to suppress the results, and the Court of Appeals affirmed.
The Court’s Holding
The Washington Supreme Court affirmed. It interpreted “any foreign substances” in former RCW 46.61.506(4)(a)(iii) to mean any kind of foreign substance capable of affecting a breath test’s reliability—not every trace amount of material, regardless of its effect. The court reasoned that treating microscopic or harmless residue as an automatic bar to admissibility would conflict with the statute’s reliability-focused purpose and produce absurd results.
The State made the required prima facie showing because a breath-test technician testified that the residual tobacco strands would not affect the Draeger test’s validity. The court clarified that expert testimony is unnecessary when an officer observes no foreign substance or the tested person denies having one. But when the possible presence of a foreign substance is debatable, the State must present expert testimony that the substance does not affect reliability. Sliger remains free to challenge the test’s accuracy and weight at trial.
Key Takeaways
- Trace material in a person’s mouth does not automatically make a Washington breath test inadmissible; the relevant question is whether the material is capable of affecting the test’s reliability.
- When the presence or effect of a possible foreign substance is debatable, the State must offer expert testimony establishing that it would not affect the test.
- Once the State makes its prima facie admissibility showing, the defendant may still contest the breath test’s reliability and evidentiary weight before the fact-finder.
Why It Matters
The decision prevents harmless residue from automatically excluding breath-test evidence while creating an expert-evidence requirement for disputed substances. A concurrence would have found Sliger’s denial sufficient without expert testimony, while the dissent argued that visible tobacco violated the statute’s bright-line requirement and Washington State Patrol procedures.