United States v. Tremayne Antwane Mitchell, 17-4317

On June 27, 2016, Newport News officers on public bike patrol smelled burning marijuana near apartment A6 in an open, ungated garden-style complex.
Officers Lyons and Marshall walked first- and second-floor common walkways, localized the odor to A6, and sniffed the apartment’s exterior windowsill and doorframe to confirm the source.
Lyons knocked; when Mitchell opened the door officers smelled a stronger marijuana odor from inside. Officers detained the two occupants outside, asked for consent to search (denied), and Lyons obtained a warrant based on an affidavit describing the odor observations.
The warrant search recovered partially burned marijuana cigarettes and a loaded firearm; Mitchell was charged federally under 18 U.S.C. § 922(g)(1).
Mitchell moved to suppress, arguing the exterior sniffs were a Fourth Amendment search and alternatively that the affidavit omitted material facts about a medical-marijuana exception; the district court granted suppression, finding the sniffs were a search and sua sponte concluding the affidavit was misleading without holding a Franks hearing.
The court of appeals reversed: it held the exterior sniffs by officers’ unenhanced sense of smell in publicly accessible areas were not a Fourth Amendment search, and the district court erred by sua sponte applying Franks procedures without a substantial preliminary showing.

Issue	Mitchell's Argument	Government's Argument	Held
Whether officers’ sniffing exterior windowsill/doorframe constituted a Fourth Amendment search	The sniffs were investigative acts by police with authority and purpose and therefore a search	A human sniff with unenhanced senses in publicly accessible areas is not a search	Not a search; sniffing outside in public-accessible/common areas is permissible
Whether suppression was required because Lyons’ affidavit knowingly/recklessly omitted material facts (Franks challenge)	Affidavit omitted or mischaracterized the sniffs, so magistrate was misled and the warrant was invalid	No substantial preliminary showing of bad faith or material omission; Franks procedures were not triggered	District court erred to sua sponte find bad faith without a Franks hearing or substantial showing; suppression unwarranted
Whether the possibility of a state medical-marijuana exception defeated probable cause	The state law exception created doubt about illegality, undermining probable cause	Odor of marijuana supplies probable cause; existence of statutory defenses does not negate probable cause	Probable cause existed; medical-marijuana exception did not defeat the magistrate’s probable-cause determination

Taylor v. United States, 286 U.S. 1 (1922) (odor may indicate criminal activity; officers may rely on smell, but entry requires a warrant)
Johnson v. United States, 333 U.S. 10 (1948) (strong odor outside a door can be persuasive evidence but entry before a warrant was error)
California v. Ciraolo, 476 U.S. 207 (1986) (observations from a public vantage point using unenhanced senses are not a Fourth Amendment search)
Florida v. Jardines, 569 U.S. 1 (2013) (use of a trained police dog to investigate the area around the home is a search because it effects an unlicensed physical intrusion on the curtilage)
Franks v. Delaware, 438 U.S. 154 (1978) (procedure for attacking warrant affidavits based on false statements or omissions; requires a substantial preliminary showing)
United States v. Leon, 468 U.S. 897 (1984) (good-faith exception and presumption of warrant validity)
Illinois v. Gates, 462 U.S. 213 (1983) (probable cause requires only a fair probability of criminal activity)
United States v. Dunn, 480 U.S. 294 (1987) (curtilage and observations from public vantage points)
Florida v. Riley, 488 U.S. 445 (1989) (naked-eye aerial observation from public airspace not a search)