Denson, an armed robbery convict out on parole, stopped reporting to his probation officer and disappeared. As we all know, this sort of behavior is heavily frowned on.
At some point, Denson opened a utility account in Witchita. Why he used his own name is anyone's guess, but he did. Police showed up at his address at 8:30 in the morning on a weekday, found the electric meter whirring away, and entered the house.* Sure enough, Denson was home. And during a protective sweep, they found a stash of guns.
Denson moved to suppress the guns, arguing that the police entry into his house was unlawful, and that even if it was lawful to enter it was not lawful to search the house once he had been arrested, and that even the protective sweep was lawful it was unlawful to seize the guns.
First, the entry: Under Payton, the police have limited authority to enter the residence of a wanted person if they have reason to believe that the aforementioned wanted person is home. In the Tenth Circuit, "reason to believe" is taken to mean reasonable suspicion. In some circuits, it's taken to mean probable cause. In this decision, the Tenth hinted that they might reconsider and go with probable cause at some point in the future, but they aren't changing their minds just yet.
In any event, the police had probable cause to believe that Denson was home. It was his only known residence, he wasn't known to have a job, it was 8:30 in the morning, he wasn't likely to be out and about whilst hiding from the police, and the electric meter was spinning furiously. Taken together, those facts created a fair probability that Denson would be home (and probable cause is just a fair probability... it's not even necessarily more likely than not).
Second argument: given that Denson was a known gang member with a violent history who was hiding from the police (and who was known to have a roommate who was also wanted), a protective sweep of the residence was justified. That said, the police almost blew this one with their stupid little radar. After all, shouldn't the police have known no one was in the house because their radar told them?
The Court makes it clear that it'll probably decide that way in the future, but that in this case there just wasn't enough information on the reliability and the capabilities of the radar. The court didn't know if the radar's ability to see who all was in a house was good enough to dispel the officers' fears that someone else dangerous might be inside.
Third, Denson argued that the guns weren't readily recognizable as contraband because the cops didn't know if someone else owned the guns. But felons aren't just prohibited from owning guns, they aren't allowed to possess them (and given Denson's ability to control the guns in his house, he constructively possessed them). So the guns were readily recognizable as contraband.
Denson's conviction was upheld.
*The police also used a radar device to see whether or not anyone was in Denson's house, and saw footprints in the snow in the back yard. The court did not consider these facts. The only reason that it would have been legal for the police to use the radar or to enter the back yard is if entry were already justified, so it's impossible to use those facts to justify entry. Sometimes it scares me how little federal agents seem to understand the law... it's like they aren't even trying. Unless it was local law enforcement pulling this crap, in which case I apologize to the feds.