In District of Columbia v. Wesby, decided January 22, the U.S. Supreme Court reaffirmed that probable cause is based on an objective totality of circumstances test. 
But Justice Ginsburg, in a notable concurring opinion, called for reexamination of Supreme Court precedent that an officer’s subjective intent should not be considered in deciding whether probable cause exists.
The issue arose in the context of a Section 1983 action.  The plaintiffs were partygoers who had been arrested by police at a vacant house.
Police received a complaint call about a loud party at the house.  When police arrived, several neighbors told police the house should be vacant. 
Police knocked on the door.  One of the partygoers let them inside, while other partygoers fled.  Inside, police found 21 people attending a “makeshift strip club.” 
The house generally wasn’t furnished and looked like a vacant property.  Beer bottles, liquor and condoms were scattered about, and the house smelled of marijuana. 
People in the house gave conflicting versions of what was taking place and who invited them.  Some said it was a bachelor party.  Others said that a woman named “Peaches” was renting the house and gave everyone permission to be there.
Police asked a partygoer to telephone Peaches.  Peaches answered and initially claimed she was renting the house and had given the partygoers permission to be there.  But when police asked her who had given her permission to use the house, she became evasive and hung up.  Police called her back, and she admitted she didn’t have permission to use the house.
Police then contacted the house’s owner.  He said he had been trying to negotiate a lease with Peaches, but they had not reached an agreement.  He said he had not given Peaches or anyone else permission to be at the house – let alone permission for a bachelor party.
At that point, police arrested the partygoers for unlawful entry in violation of District of Columbia law.
The charges were eventually dropped, but the partygoers sued the police for arresting them without probable cause.
The lower courts ruled in favor of the partygoers.  They concluded that police lacked probable cause to arrest the partygoers for unlawful entry, since officers were told that Peaches had invited them, and nothing officers learned in their investigation showed that the partygoers knew or should have known that they were entering against the owner’s wishes.
Totality of Circumstances
The Supreme Court reversed. 
Probable cause requires only a probability or substantial chance of criminal activity, not an actual showing of such activity, the Supreme Court said.  Whether probable cause exists is based on what an objectively reasonable officer would perceive under the totality of circumstances.
 “Considering the totality of circumstances, the officers made an entirely reasonable inference that the partygoers were knowingly taking advantage of a vacant house as a venue for their late-night party,” the Court held. 
First, the condition of the house and conduct of the partygoers allowed officers to make “common sense conclusions” about what was taking place.  “[M]ost homeowners do not invite people over to use their living room as a strip club,” the Court said, and invited guests generally don’t flee from police.  This was “certainly suggestive of wrongdoing.”
Second, the partygoers’ conflicting and “implausible” answers to what was taking place in the house “suggested their guilty state of mind.”
The lower courts, in concluding that officers lacked probable cause, failed to follow two well-established principles, the Court said.  First, the lower courts viewed each fact in isolation, rather than as a totality.  Second, the lower courts dismissed any circumstances that were “susceptible of innocent explanation.” 
Probable cause does not require officers to rule out a suspect’s innocent explanation for suspicious facts, the Court explained.  “The relevant inquiry is not whether particular conduct is ‘innocent’ or ‘guilty,’ but the degree of suspicion that attaches to particular types of noncriminal acts.”
The question is whether “a reasonable officer could conclude – considering all of the surrounding circumstances, including the plausibility of [innocent explanations] – that there was a substantial chance of criminal activity,” the Court concluded.  “The circumstances here certainly suggested criminal activity.” 
A second issue in the case was whether the officers were entitled to qualified immunity.  While acknowledging that it was unnecessary to decide that issue in light of the probable cause ruling, the Court nevertheless held that the officers were entitled to qualified immunity.
Concurring Opinions
Justice Ginsburg concurred, but noted that police had arrested the partygoers based on an error of law.  Police believed that the absence of the house owner’s consent, standing alone, justified the arrests.  But an essential element of unlawful entry is that the partygoers themselves “knew or should have known” that their entry was unlawful.
 “A number of commentators have criticized the path we charted in Whren v. United States, 517 U.S. 806 (1996), and follow-on opinions, holding that an arresting officer’s state of mind … is irrelevant to the existence of probable cause,” she said. 
 “The Court’s jurisprudence, I am concerned, sets the balance too heavily in favor of police unaccountability to the detriment of Fourth Amendment protection,” she said.  “I would leave open, for reexamination in a future case, whether a police officer’s reason for acting, in at least some circumstances, should factor into the Fourth Amendment inquiry.”
Given the current state of the law, however, she agreed with the majority.
Justice Sotomayor concurred, but said she would not have decided the probable cause question.  Instead, she would have reversed the lower courts by holding that the police were entitled to qualified immunity.