United States v. Ostertag.
No. 25-8055. 9/8/2026. D.Wyo. Judge Murphy. Vehicle Search—Narcotics Detection Dog Sniff—Fourth Amendment—Probable Cause—18 USC § 922(g)(1)—Facial and As-Applied Challenges.
September 8, 2026
Wyoming Highway Patrol Sergeant Bracken pulled Ostertag’s vehicle over on I-80 for failing to signal a turn. Trooper Martinez and his narcotics detection dog Becky were called to the scene. Bracken ran a record check on Ostertag while Becky performed an initial sniff on the exterior of Ostertag’s vehicle from the side of the road (open-air sniff). Martinez then brought Becky closer to the vehicle, and she ran back and forth along the passenger side, then repeatedly jumped and placed her front paws on the vehicle. Shortly thereafter she stopped jumping and sat still, remaining focused on the vehicle. Martinez told Bracken that Becky had shown a positive alert behavior, so Bracken removed Ostertag from his vehicle. Martinez and Bracken then searched the interior, where they found a 9mm pistol with an obliterated serial number between the driver’s seat and the center console. Ostertag had a prior felony conviction and was indicted for possessing a firearm as a felon in violation of 18 USC § 922(g)(1) and possessing a firearm with an obliterated serial number in violation of 18 USC § 922(k). Ostertag moved to suppress the evidence found in the vehicle search, asserting it resulted from an unconstitutional search for which the officers lacked probable cause. Following a hearing, the district court denied the motion. Ostertag also moved to dismiss his indictment, raising both facial and as-applied challenges to § 922(g)(1). The district court ruled that Ostertag’s challenges to § 922(g)(1) were foreclosed by then-current Tenth Circuit law and concluded that § 922(k) did not implicate the Second Amendment. Ostertag subsequently pleaded guilty pursuant to a conditional plea agreement that preserved his right to appeal the district court’s rulings on his motion to suppress and on his motions to dismiss the indictment. The district court dismissed the charge of possessing a firearm with an obliterated serial number on the government’s motion.
On appeal, Ostertag argued that Becky’s open-air sniff on his vehicle’s exterior from the side of a public highway amounted to an unconstitutional search in violation of the Fourth Amendment. Illinois v. Caballes, 543 U.S. 405, 408 (2005), held that a sniff performed by a well-trained narcotics-detection dog on a vehicle’s exterior during a lawful traffic stop on a public road was, categorically, not a search. Caballes was premised on an interest in possessing contraband being not legitimate, and the fact that a sniff by a well-trained narcotics-detection dog discloses only the presence or absence of narcotics, which is a contraband item. Ostertag argued for deviation from this precedent, maintaining that Becky is trained to detect the scent of certain controlled substances, and the scent of these substances does not always reveal unlawful activity because, for example, marijuana smells like hemp; and the scent of methamphetamine and fentanyl could be traced to legally prescribed medication, the possession of which may reveal medical or mental health information. Thus, Becky’s sniff intrudes upon reasonable expectations of privacy. Second, Ostertag analogized a narcotics-detection dog’s sniff to the use of a thermal-imaging device aimed at a private home from a public street found unlawful in Kyllo v. United States, 533 U.S. 27 (2001), asserting that Becky is capable of detecting lawful activity and her sniff was thus an unconstitutional search. However, Ostertag failed to meet his burden of showing a legitimate expectation of privacy because there is a reduced expectation of privacy in a vehicle as compared to a house, and the asserted privacy interest in medical and mental health information is several inferential leaps removed from the limited information a dog-sniff might uncover. Becky’s open-air sniff therefore did not constitute a search under the Fourth Amendment.
Ostertag also contended that he was again subjected to an unlawful search when Becky put her front paws on his vehicle as she continued to sniff. Even assuming for argument’s sake that Becky’s physical contact with Ostertag’s vehicle, combined with her sniff, initiated a search, the record shows that Becky positively alerted after performing an open-air sniff but before placing her paws on the vehicle, so the government established probable cause. Accordingly, there was no Fourth Amendment violation.
Ostertag further asserted a facial and an as-applied challenge to § 922(g)(1) in arguing that the district court erred in denying his motion to dismiss the indictment. However, Ostertag conceded that Vincent v. Bondi, 127 F.4th 1263, 1266 (10th Cir. 2025), which held that § 922(g)(1) may be applied against those without violent felony convictions, is binding precedent and thus compels affirmance of the district court’s ruling. And his facial challenge fails by extension.
The judgment was affirmed.