State v. Cook, 444 P.3d 877

Shortly after midnight on Oct. 29, 2016, Deputy Jacobson followed and stopped Samantha Cook’s car after observing it lacked front and rear license plates; a temporary registration permit was posted in the rear window but was obscured by condensation.
Jacobson could not read the permit from his patrol vehicle; after stopping he approached, wiped condensation, confirmed the permit was valid, then contacted Cook, detected marijuana odor, obtained consent/admission, searched the vehicle, and found controlled substances.
Cook moved to suppress evidence, arguing the stop lacked reasonable suspicion and that Idaho Code § 49-432(4) (temporary permits must be posted where “readily legible”) is unconstitutionally vague as applied.
The district court denied the motion, relying on State v. Kinch to find reasonable suspicion; the Court of Appeals affirmed. This Court granted review.
The Idaho Supreme Court evaluated the statute under the void-for-vagueness doctrine (due process), focusing on whether the statute and related administrative rules/case law gave ordinary persons fair notice and prevented arbitrary enforcement.
The Court concluded § 49-432(4) failed to specify (a) from what distance a permit must be legible, (b) whether it must be kept “clearly visible” or “free from foreign materials,” and (c) the Transportation Board had not promulgated a required form—making the statute unconstitutionally vague as applied to Cook.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether the traffic stop was supported by reasonable suspicion from an unreadable temporary permit under Idaho Code § 49‑432(4)	Cook: statute is unconstitutionally vague as applied; posting a valid permit satisfied the statute even if it later became unreadable by condensation	State: permit not "readily legible" while driving; Kinch permits an officer to stop when permit cannot be read, supplying reasonable suspicion	Court held statute is unconstitutionally vague as applied; lack of notice meant stop lacked lawful basis, suppression required
Whether § 49‑432(4) gives motorists adequate notice of required conduct (distance/readability/maintenance)	Cook: statute and agency rules do not define readability distance or maintenance obligations; ordinary motorists lack fair notice	State: Salois and Kinch interpretability supports enforcement when permit is not readily legible	Court held the statute (and Board rules/case law) fail to give clear standards (distance/visibility/maintenance), inviting arbitrary enforcement; statute vague as applied

State v. Kinch, 159 Idaho 96 (Ct. App. 2015) (court treated an unreadable, crumpled/condensed temporary permit as not "readily legible" and allowed inference of invalidity)
State v. Salois, 144 Idaho 344 (Ct. App. 2007) (a properly posted temporary permit is presumed valid; only obvious, discernable invalidity overcomes presumption)
State v. Korsen, 138 Idaho 706 (Idaho 2003) (explaining void‑for‑vagueness doctrine and need for clarity in criminal statutes)
State v. Larsen, 135 Idaho 754 (Idaho 2001) (void‑for‑vagueness principles and as‑applied analysis)
Village of Hoffman Estates v. Flipside, 455 U.S. 489 (U.S. 1982) (void‑for‑vagueness framework for statutes regulating conduct)
Grayned v. City of Rockford, 408 U.S. 104 (U.S. 1972) (statutes must give fair notice and avoid arbitrary enforcement)

For these reasons the Court reversed the denial of Cook’s motion to suppress, vacated her conviction, and remanded for further proceedings.