Probable Cause in Practice

Probable Cause in Practice

The probable cause test is easy to state and harder to apply, because its working terms (reasonably trustworthy facts, a prudent person, a substantial chance of crime) take their content from the facts in front of the officer. Beck showed the standard failing on a record made of conclusions. Two modern decisions show it succeeding on records made of facts: Maryland v. Pringle and District of Columbia v. Wesby. They are taught together here because both resolve one question. Did the facts known to the officer, viewed as a whole from the standpoint of an objectively reasonable officer, show a substantial chance that a crime was occurring?¹

The phrase "viewed as a whole" is the reason the two cases belong in one lesson. Probable cause concerns probabilities, so it depends on the totality of the circumstances, and for that reason it resists reduction to a neat set of legal rules. It requires only a probability or substantial chance of criminal activity, not an actual showing of crime, and the Court has said the standard is "not a high bar."² A probability is judged by weighing everything together, so a single fact with an innocent explanation does not defeat it. In Wesby the house had working electricity, blinds, toiletries, and food in the refrigerator, all of which a resident might leave behind. The Court observed that those facts were not necessarily inconsistent with a vacant house and then weighed them against the bare rooms, the neighbors' reports, and the partygoers' conduct.³ A court that discarded each fact because it could be innocent would almost never find probable cause, since few single facts prove a crime.

The two cases test the standard at different points. Pringle asks how a crime is tied to a particular person when contraband turns up in a shared space and no one claims it. At 3:16 a.m. an officer stopped a car for speeding with three men inside, found rolled-up cash in the glove compartment and cocaine behind the rear armrest, and arrested all three after each denied ownership. The Court held there was probable cause to arrest Pringle, the front-seat passenger.⁴ Wesby asks how an officer may infer a suspect's state of mind from the condition of the premises and the behavior of the people in them, since the partygoers argued the officers had no reason to think they knew their entry was unwanted.⁵ On an exam stem, the usual mistake in both settings is to evaluate one fact at a time and reject each as consistent with innocence, when the standard asks what the facts show together. The next section takes Pringle first.

Contraband and Occupants

Probable cause to arrest must be particularized to the person seized, meaning the facts must show a fair probability both that a crime was committed and that the person taken into custody committed it.⁶ The second half of that requirement becomes difficult when police find contraband in a space several people share and nobody admits it is theirs, since the discovery shows that an offense occurred without saying who committed it. Maryland v. Pringle answers that difficulty for a passenger car, and the answer shows how a belief about one person can rest on an inference drawn from the setting, even though the officer never saw that person touch the contraband.⁷

The facts are compact. At 3:16 a.m. a Baltimore County officer stopped a Nissan Maxima for speeding, with Partlow driving and owning the car, Pringle in the front passenger seat, and Smith in the back.⁸ When Partlow opened the glove compartment for the registration, the officer saw a large amount of rolled-up cash, and after Partlow consented to a search the officer found $763 there and five glassine baggies of cocaine behind the back-seat armrest, which had been upright and flat against the seat until the officer pulled it down.⁹ The officer asked about ownership and told the men that if no one admitted it, all three would be arrested.¹⁰ Each man denied owning the cocaine and the money, none offered any information about who did, and the officer arrested all three.¹¹ Pringle later confessed that the cocaine was his and that the others knew nothing of it, and the other two were released.¹² Pringle then moved to suppress the confession as the fruit of an illegal arrest, so the only issue was whether probable cause existed at the moment of arrest.¹³

The Court began with the method that governs every review of this kind: examine the events leading up to the arrest, then decide whether those historical facts, viewed from the standpoint of an objectively reasonable police officer, amount to probable cause.¹⁴ The facts it weighed were that Pringle was one of three men in a car at 3:16 a.m., that the rolled-up cash lay in the glove compartment directly in front of him, that the cocaine behind the armrest was accessible to all three, and that none of the men offered any information about the ownership of the money or the drugs.¹⁵ From those facts the Court found it an entirely reasonable inference that any or all three occupants knew of the cocaine and exercised dominion and control over it, so a reasonable officer could conclude there was probable cause to believe Pringle had committed possession, either alone or jointly.¹⁶

Knowledge and dominion are what an officer must connect to a person before that person can be tied to possession, and an officer cannot watch either one happen inside someone's head. The inference from the setting therefore has to do the work that direct observation cannot, and the Court explained why the setting supports it. The officer could reasonably infer a common enterprise among the three men, because the quantity of drugs and cash indicated the likelihood of dealing, an enterprise to which a dealer would be unlikely to admit an innocent person who could furnish evidence against him.¹⁷ That chain runs through each rider individually. A dealer with cash in front of the passenger seat and cocaine within reach of the back seat is unlikely to be carrying a stranger, so each occupant is probably a participant, and an arrest of any one of them rests on that probability. The standard tolerates this, because probable cause deals in probabilities and resists quantification into percentages.¹⁸ Pringle's later confession does not change the analysis, because probable cause is judged on the historical facts known when the officer acted, so a later development can neither create it nor erase it.¹⁹

Pringle resisted this conclusion by calling the case one of guilt by association and relying on Ybarra v. Illinois and United States v. Di Re, and the Court found that reliance misplaced.²⁰ In Ybarra officers held a warrant to search a tavern and its bartender for evidence of drug possession. On entering, they patted down the customers, and a cigarette pack taken from Ybarra's pocket held six tinfoil packets of heroin.²¹ The Court there stated that a person's "mere propinquity to others independently suspected of criminal activity does not, without more, give rise to probable cause to search that person."²² It held that the warrant did not authorize searching all of the patrons and that officers could not pat them down without individualized suspicion.²³ Ybarra was a search case, but the demand for a belief particularized to the person is the same one that governs arrests, which is why Pringle treated it as the argument to answer.²⁴

The two decisions apply one rule to different links between person and crime. In Ybarra the independent suspicion attached to the bartender and the premises, and the customers had only their presence in common with that suspicion. In Pringle the contraband sat in the passenger compartment of a small car, the cash was directly in front of the arrested passenger, the cocaine was accessible to all three men, and the quantity pointed toward dealing, which made a shared enterprise a reasonable inference.²⁵ The occupants' failure to offer any information about ownership was also among the facts the Court counted.²⁶ The question in a new fact pattern is whether the circumstances themselves connect each person to the contraband. Standing near a person who is suspected for other reasons does not do that.

A stem that places three people in a car with drugs invites the argument that all three may be arrested, and the opposite argument that no passenger ever may be. Students lose this issue by reading Pringle as a rule that presence in the car is enough, when the Court relied on the small shared space, the accessibility and quantity of the contraband, and the occupants' silence about ownership. The same students reverse the error when a stem describes a person who merely stood near someone with a warrant against them, since Ybarra shows that proximity with nothing more leaves probable cause unparticularized. The outcome depends on whether the facts, taken together, make joint possession a reasonable inference as to the person arrested.

Inferences From the Scene

Pringle inferred what three men in a car knew about cocaine from where the drugs lay and how much of them there was, and District of Columbia v. Wesby applies the same method to a different missing link. The offense there was unlawful entry, and the partygoers did not dispute that they had entered the house against the owner's will. They argued instead that the officers had no reason to believe the partygoers "knew or should have known" their entry was unwanted, which left the knowledge element of the offense without support.²⁸ The arrest therefore turned on a mental state, which no officer can watch happen, and the question became what the scene itself revealed about it.

The facts reached the officers in layers. Around 1 a.m. they responded to a complaint of loud music and illegal activity at a house that several neighbors, including a former neighborhood commissioner, said had been vacant for months.²⁹ Inside they found almost no furniture beyond a few padded metal chairs and one bare mattress, the smell of marijuana, beer bottles and cups of liquor on a dirty floor, a makeshift strip club in the living room, and, upstairs, a naked woman with several men on the mattress that was the only bed in the house.³⁰ Many partygoers scattered or hid when they saw the uniformed officers.³¹ The accounts the officers collected did not match, since some guests described a bachelor party without identifying the bachelor, and others claimed invitations from a woman named Peaches who was not present.³² By phone Peaches sounded nervous, agitated, and evasive, first claimed to be renting the house and to have approved the party, and finally admitted she had no permission, and the owner confirmed that he had allowed no one to be there.³³ The officers then arrested all 21 partygoers for unlawful entry.³⁴

The Court held that, considering the totality of the circumstances, the officers made an "entirely reasonable inference" that the partygoers were knowingly using a vacant house as a venue for a late-night party.³⁵ The opinion sorts the evidence into two groups. The condition of the house pointed toward vacancy, because of the neighbors' reports, the empty rooms, and the absence of boxes, moving supplies, or clothes in closets, which gave the officers reason to doubt that Peaches had just moved in.³⁶ The conduct of the partygoers pointed toward people who expected no objection from anyone with authority over the house: a party still going strong after 1 a.m. with music audible outside, marijuana smoke, a strip club in the living room, and sex in the bedroom.³⁷ The case reached the Court as a damages suit for false arrest in which the officers' qualified immunity was also at issue, and this section addresses only the Fourth Amendment question whether probable cause existed.³⁸

The step from those facts to knowledge is a generalization about how people ordinarily behave. Most homeowners do not live in near-barren houses, and most do not invite people over to turn the living room into a strip club, to have sex in the bedroom, to smoke marijuana indoors, and to leave the floors filthy, so the officers could infer that the partygoers knew the party was unauthorized.³⁹ A far smaller scene can carry the same weight. In Schmerber v. California the officer who reached the scene of an accident smelled liquor on the driver's breath and saw eyes that were bloodshot, watery, and glassy, and he saw similar symptoms at the hospital within two hours, and the Court found plainly probable cause to arrest for driving while intoxicated.⁴⁰ Intoxication is a condition the officer cannot measure on the spot, so the smell and the appearance serve as the observable signs from which a prudent officer concludes it is probable. Wesby asks for the same step with a mental state in place of a bodily condition, and the observable signs are the condition of the premises and the behavior of the people in them.

The reason this inference is legitimate lies in how probabilities combine. Each fact standing alone had an innocent reading, and the Court said so about the working electricity, the blinds, the toiletries, and the food in the refrigerator.⁴¹ The relevant question is how likely it is that a lawful occupant or an invited guest would present all the circumstances at once: a barren house reported vacant for months, a party conducted in ways no ordinary host permits, guests who scatter and hide, stories that conflict, and a supposed host who cannot vouch for anyone. Each added circumstance eliminates some innocent explanations until only an improbable one remains. Probable cause asks only for a probability or substantial chance of criminal activity, so the officers did not have to rule out every innocent account, a burden that would demand the very proof of guilt a trial exists to supply.⁴² The lower courts had found probable cause lacking, and the Court's decision corrects the habit of treating each fact in isolation and rejecting any circumstance that could have an innocent explanation.⁴³

The partygoers' scattering raises a further caution, because flight is the kind of fact that can mislead. In Wong Sun v. United States agents seeking a suspect named Toy told the person at the laundry door that they had come for laundry and dry cleaning, and Toy ran down the hall when the agent then revealed he was a narcotics officer.⁴⁴ The Court treated that flight as ambiguous conduct, since it signified guilty knowledge no more clearly than a natural desire to repel an apparently unauthorized intrusion, and it refused to let vague suspicion become probable cause through a reaction the agents' own ruse had provoked.⁴⁵ Courts have long doubted the probative value of flight for a related reason, which is that innocent people sometimes run out of fear.⁴⁶ The two decisions differ in what surrounded the flight. In Wesby the partygoers scattered when uniformed officers arrived openly, and the scattering was one circumstance among many, none of the others induced by the police. In Wong Sun the flight was offered to corroborate an untested accusation, and the officer's deception had supplied an innocent reason to run.

Exam stems built on this doctrine usually list a handful of observations, each with a plausible innocent reading, and invite the argument that probable cause is missing because no observation proves the offense. Students lose points by accepting an innocent explanation for a single fact as though it ended the analysis, when the standard asks what the facts show together. The same students overcorrect when a stem supplies a lived-in home, a host whose account the officers can verify, or a flight the officers themselves provoked, because those facts remove the inference that did the work in Wesby. The result depends on whether the combined circumstances make the contested element, here knowledge of unauthorized entry, a substantial chance.