State v. Thomas (A173467), 524 P.3d 969

Michael Scott Thomas was convicted by a jury of misdemeanor DUII for driving under the influence of intoxicants based on, inter alia, a urinalysis (UA).
Thomas appealed, raising four issues: (1) the trial court admitted the UA without applying Brown/O’Key foundational standards for scientific evidence; (2) admission of the UA was an OEC 403 abuse of discretion; (3) the trial court’s use of UCrJI 1008 (inferences) was erroneous; and (4) the court refused Thomas’s proposed inference instruction.
The UA at issue was performed in an accredited/licensed toxicology laboratory.
ORS 813.131(5), as amended in 2009, expressly makes a valid chemical analysis of urine admissible at trial if performed in an accredited or licensed toxicology laboratory; the legislative history states the amendment was intended to override Tripathi.
The Court of Appeals reviewed legal questions de novo and appellate discretionary rulings for abuse of discretion, and affirmed the trial court on all assignments of error.

Issue	Plaintiff's Argument (State)	Defendant's Argument (Thomas)	Held
Admissibility of UA under statutory scheme	ORS 813.131(5) makes UAs from accredited labs categorically admissible; no additional Brown/O’Key foundation required	Trial court should have required Brown/O’Key foundational proof for scientific evidence before admitting UA	Affirmed — statute’s plain terms make qualifying UAs admissible; Brown/O’Key not required post-amendment
OEC 403 exclusionary claim	Probative value of UA not substantially outweighed by danger of unfair prejudice; trial court acted within discretion	UA should have been excluded as more prejudicial than probative; record insufficient to review exercise of discretion	Affirmed — record adequate; no abuse of discretion under OEC 403
Use of UCrJI 1008 (uniform inference instruction)	UCrJI 1008 is proper; jurors may draw reasonable inferences alongside correct beyond-a-reasonable-doubt instruction	The uniform instruction lessens the State’s burden of proof and is erroneous	Affirmed — consistent with precedent (Hines) and does not conflict with reasonable-doubt instruction
Refusal to give defendant’s special inference instruction	Uniform instruction and other instructions adequately cover inferences and burden of proof	Requested instruction was necessary to prevent speculative stacking of inferences	Affirmed — trial court need not give duplicative/supplemental instruction when law is adequately covered

State v. Brown, 297 Or 404 (Or. 1984) (articulated foundational standards for scientific evidence)
State v. O’Key, 321 Or 285 (Or. 1995) (scientific-evidence foundational requirements)
State v. Tripathi, 226 Or App 552 (Or. App. 2009) (previously excluded UA for lack of foundational showing)
State v. Hines, 84 Or App 681 (Or. App. 1987) (upheld inference instruction alongside beyond-a-reasonable-doubt instruction)
State v. Hedgpeth, 365 Or 724 (Or. 2019) (reasonable inferences may give rise to competing inferences; jury decides)
State v. Rainey, 298 Or 459 (Or. 1985) (governs limits on certain jury instructions)
Couey v. Atkins, 357 Or 460 (Or. 2015) (legislative-history materials probative of legislative intent)