by Kimberly La Fronz*

When conducting a warrantless search or seizure, must a police officer have probable cause for all elements of the crime, including mens rea? In this Contribution, Kimberly La Fronz (’18) discusses what the circuits include in their totality of the circumstances analysis to determine probable cause. This Contribution argues that in order to effect a warrantless arrest a police officer must have probable cause with respect to every element of the crime in order to effect a warrantless arrest and must not ignore exonerating evidence in their totality of the circumstances analysis.


The Fourth Amendment aims to strike a balance between the fundamental right to be free from unreasonable searches and seizures and allowing law enforcement officers to take effective action to protect the public interest.2 Yet, because the standard for effecting warrantless arrests relies on a nebulous “totality of the circumstances” analysis,3 exactly what information a police officer must consider before effecting such an arrest is unclear. While much of the probable cause calculation is settled law at this point4, it remains undecided whether an officer must have probable cause for every element of a crime, including mens rea, and how much attention officers must pay to evidence tending to negate that mens rea. Ultimately, this Contribution will argue that in order to effect a warrantless arrest a police officer must have probable cause with respect to every element of the crime in order to effect a warrantless arrest and must not ignore exonerating evidence in their totality of the circumstances analysis.

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Precedent is clear that, in order to make a valid arrest without a warrant, the arresting officer must analyze probable cause at least as stringently as the warrant process would5 since an arrest without a warrant “bypasses the safeguards provided by an objective predetermination of probable cause.”6 To meet this requirement, the officer is required to consider the “totality of the circumstances,” a standard first instituted by the United States Supreme Court in Illinois v. Gates to determine whether probable cause existed to search a house.7 The Court emphasized that the totality of the circumstances analysis was meant to be a “commonsense, practical” analysis.8

Yet case law is often unclear as to what information must be considered in the totality of the circumstances analysis and what officers must have probable cause of in order to arrest a person. Prior to Illinois v. Gates, the Supreme Court held that a warrantless arrest was unconstitutional absent “information hinting further at the knowledge and intent required as elements of the felony under the statute.”9 In United States v. Di Re, the officer made an arrest because he saw illegal gambling coupons in a car, but the Court noted that presence alone did not speak to the knowledge and intent requirements of the statute.10 Yet, subsequently in Maryland v. Pringle, where multiple men were found in a car with controlled substances, the Court permitted the arresting officers to infer the knowledge mens rea for each individual11 While officers need not have trial-level proof of every element of the crime at the moment of arrest,12 the Pringle and Di Re decisions indicate that mens rea must play a part in the totality of the circumstances analysis in some way. The remaining question is whether officers must have specific facts indicating the requisite mens rea or whether a mere inference will always suffice.

Though Pringle seemed to suggest that an inference is sufficient, circuit courts have split on the issue. The Fourth, Seventh, and Ninth Circuits hold that an officer need not establish probable cause for each element of an offense,13 while the Third, Sixth, Eighth, and D.C. Circuits hold that probable cause must extend to every element of an offense.14 One of the earliest cases to adopt the understanding of probable cause as not requiring probable cause for every element, United States v. Sevier, focused on the idea that probable cause should be practical and nontechnical.15 But as the Eighth Circuit said, “[f]or probable cause to exist, there must be probable cause for all elements of the crime, including mens rea.”16

By its very nature, the totality of the circumstances test requires an officer to consider all circumstances related to a possible crime. A number of the circuit courts have emphasized that law enforcement cannot ignore or disregard exculpatory facts in their probable cause analysis.17 Necessarily, the totality of the circumstances analysis, while providing that law enforcement officers can look at the entirety of the circumstances surrounding the alleged crime, also requires that they consider facts tending to dissipate probable cause.18 To hold otherwise would render probable cause analysis a nullity, because officers could claim probable cause despite significant facts to the contrary.

It is a necessary aspect of the totality of the circumstances analysis that “police officers may not ignore easily accessible evidence and thereby delegate their duty to investigate and make an independent probable cause determination based on that investigation.”19 The probable cause inquiry “requires officers to reasonably interview witnesses readily available at the scene, investigate basic evidence, or otherwise inquire if a crime has been committed at all before invoking the power of a warrantless arrest and detention.”20 Failure to investigate exculpatory or other information prior to arrest can prevent the establishment of probable cause.21

In BeVier v. Hucal, the Seventh Circuit held that an arrest was not valid without evidence of the requisite mens rea and that an officer’s decision to ignore information tending to negate mens rea opened him up to a valid § 1983 claim.22 The Seventh Circuit does not require probable cause of every element of the crime23 yet still prohibits officers from ignoring exculpatory evidence on the subject of mens rea. And circuits on both sides of the split agree that it is in keeping with law enforcement’s duty to examine the totality of the circumstances that officers may not close their eyes to facts that would clarify the circumstances of an arrest, particularly where it is unclear whether a crime had taken place or where further investigation may exonerate the suspect.24 While law enforcement need not have proof beyond a reasonable doubt at the time of arrest,25 they must at least conduct a reasonably thorough investigation where there are no exigent circumstances26 or where minimal, reasonable further investigation would shed light on the events.27 This logic demonstrates that the workable solution to questions of mens rea at the moment of arrest is to return to a more robust understanding of the totality of the circumstances analysis that focuses on the actual totality, both exculpatory and inculpatory.

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Advocates of not requiring probable cause for mens rea argue that asking officers to look into the state of mind would frustrate legitimate law enforcement purposes.28 However, under the probable cause of mens rea standard, officers need not peer into suspects’ minds in order to ascertain their mental state at the time of a possible crime. While officers cannot know what a suspect’s exact state of mind is, they also may not ignore evidence suggesting a suspect lacks the requisite mens rea. For most crimes, a guilty mens rea is what makes otherwise innocent behavior into criminal action. Without evidence of that mens rea, criminal suspects risk having their lives disrupted by court proceedings or pre-trial detention despite having engaged in behavior not specifically criminalized by the statute.

Evidence tending to support or negate the existence of the requisite mens rea is often readily available at the time of arrest. As a start, criminal suspects may make statements either inculpating or exculpating themselves. Yet officers do not have to just take suspects at their words.29 As was the case in Maryland v. Pringle, officers make inferences about whether knowledge or intent existed by, for example, looking at how visible the illicit substances were or how obvious the criminal behavior was.30 The key point here is that officers must not only look at evidence that supports the guilty mens rea; the totality of the circumstances analysis necessarily requires them to also examine evidence tending to negate mens rea, just as they must for any other piece of exculpatory or undisputed information.

In order to abide by this proposed standard, law enforcement officers do not need to conduct an exhaustive investigation prior to arrest. Instead, effective and constitutional law enforcement includes learning “what easily could have been learned, and in common prudence should have been,”31 or performing minimal investigation that “would have reduced any suspicion created by the facts police had discovered.”32 Already, law enforcement officers check the Vehicle Identification Number of a car or ask its driver for the vehicle’s registration papers prior to concluding that a car is stolen. It is not unreasonable to ask that an officer similarly ask suspects about the circumstances of the alleged crime or consider information easily produced or readily available at the scene that sheds light on a suspect’s state of mind. That basic level of inquiry would satisfy the proposed inquiry into the suspect’s mens rea.

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An understanding of the totality of the circumstances analysis that considers both inculpatory and exculpatory information with regards to the suspect’s mens rea and requires minimal investigation in unclear circumstances bridges the gap between the inability of law enforcement officers to read the minds of criminal suspects and the right of people to be free from unreasonable arrests. By doing so, it still allows law enforcement to do their jobs quickly and on the scene but prevents wrongful arrests and the many consequences that can accompany such unlawful arrests. In the compromise between these important interests, requiring law enforcement officers to examine the true totality of the circumstances strikes the right balance.


* Kimberly La Fronz is a 3L at New York University School of Law. This piece is a commentary on a problem written for the 2017 Herbert Wechsler National Criminal Moot Court Competition at the University of Buffalo School of Law. The issue in the problem centered on whether law enforcement officers must have probable cause of the requisite mens rea to effect an arrest and how much investigation officers must do for that element of the crime. The views expressed in this article do not necessarily represent the views of the author on this point. Rather, this article is a distillation of one side of an argument assigned to the team.
2. Brinegar v. United States, 338 U.S. 160, 176 (1949) (The probable cause requirement of the Fourth Amendment is a compromise that “seek[s] to safeguard citizens from rash and unreasonable interferences with privacy and from unfounded charges of crime. [It] also seek[s] to give fair leeway for enforcing the law in the community’s protection.”).
3. Maryland v. Pringle, 540 U.S. 366, 371 (2003) (“The probable-cause standard is incapable of precise definition or quantification into percentages because it deals with probabilities and depends on the totality of the circumstances.”).
4. Corbin Houston, Probable Cause Means Probable Cause: Why the Circuit Courts Should Uniformly Require Officers to Establish Probable Cause for Every Element of an Offense, 2016 Univ. of Chicago Legal Forum 809, 809 (2016) (“While many of the nuances of probable cause are settled law, there still remains much ambiguity surrounding the doctrine’s application by law enforcement in the area of warrantless arrests.”).
5. Wong Sun v. United States, 371 U.S. 471, 479 (1963) (“Whether or not the requirements of reliability and particularity of the information on which an officer may act are more stringent where an arrest warrant is absent, they surely cannot be less stringent than where an arrest warrant is obtained.”).
6. Beck v. Ohio, 379 U.S. 89, 96 (1964).
7. See Illinois v. Gates, 462 U.S 213, 230-31 (1983).
8. Id. at 230.
9. United States v. Di Re, 332 U.S. 581, 592 (1948).
10. Id. (“at the time of the arrest the officers had no information implicating Di Re and no information pointing to possession of any coupons, unless his presence in the car warranted that inference. Of course they had no information hinting further at the knowledge and intent required as elements of the felony under the statute.”).
11. Maryland v. Pringle, 540 U.S. 366, 373 (2003) (“Here we think it was reasonable for the officer to infer a common enterprise among three men. The quantity of drugs and cash in the car indicated the likelihood of drug dealing, an enterprise to which a dealer would be unlikely to admit an innocent person with the potential to furnish evidence against him.”).
12. Adams v. Williams, 407 U.S. 143, 149 (1972) (“Probable cause does not require the same type of specific evidence of each element of the offense as would be needed to support a conviction.”).
13. See Houston, supra note 4, at 809; Cilman v. Reeves, 452 F. App’x 263, 270-71 (4th Cir. 2011); Spiegel v. Cortese, 196 F.3d 717, 724 n.1 (7th Cir. 1999); Gasho v. United States, 39 F.3d 1420, 1428 (9th Cir. 1994).
14. See Houston, supra note 4, at 809-10; Williams v. City of Alexander, 772 F.3d 1307, 1312 (8th Cir. 2014); Wesby v. District of Columbia, 765 F.3d 13, 20 (D.C. Cir. 2014); United States v. Joseph, 730 F.3d 336, 342 (3d Cir. 2013); Thacker v. City of Columbus, 328 F.3d 244, 256 (6th Cir. 2003).
15. United States v. Sevier, 539 F.2d 599, 603 (6th Cir. 1976) (citing Beck v. Ohio, 379 U.S. 89 (1964)). See also Houston, supra note 4, at 814 (“The Sevier court likely seized on Beck’s language that ‘the rule of probable cause is a practical, nontechnical conception affording the best compromise that has been found for accommodating…often opposing interests.’”).
16. Williams, 772 F.3d at 1312.
17. See, e.g., Bigford v. Taylor, 834 F.2d 1213, 1218 (5th Cir. 1988) (officers “may not disregard facts tending to dissipate probable cause”); BeVier v. Hucal, 806 F.2d 123, 128 (7th Cir. 1986) (“The continuation of even a lawful arrest violates the Fourth Amendment when police discover additional facts dissipating their earlier probable cause”); Kuehl v. Burtis, 173 F.3d 646, 650 (8th Cir. 1999) (“An officer contemplating an arrest is not free to disregard plainly exculpatory evidence”); Baptiste v. J.C. Penney Co., 147 F.3d 1252, 1259 (10th Cir. 1998) (officers “may not ignore available and undisputed facts”).
18. Bigford, 834 F.2d at 1218 (“As a corollary…of the rule that the police may rely on the totality of facts available to them in establishing probable cause, they also may not disregard facts tending to dissipate probable cause.”).
19. Baptiste, 147 F.3d at 1259.
20. Romero v. Fay, 45 F.3d 1472, 1476-77 (10th Cir. 1995).
21. See, e.g., United States v. Ramirez-Rivera, 800 F.3d 1, 28 (1st Cir. 2015) (failure to attempt to corroborate informant’s tip vitiated probable cause); Sevigny v. Dicksey, 846 F.2d 953, 958 (4th Cir. 1988) (failure to learn what easily could have been learned vitiated probable cause); Bigford, 834 F.2d at 1218 (failure to complete minimal investigation vitiated probable cause); BeVier, 806 F.2d at 128 (failure to pursue reasonable avenues of investigation vitiated probable cause); Kuehl, 173 F.3d at 650 (failure to conduct a reasonably thorough investigation vitiated probable cause).
22. 806 F.2d at 128 (“Because this information [about the child’s condition and parents’ behavior] could have been easily obtained and was necessary before concluding that Robert and Annette had intentionally neglected their children, Hucal was unreasonable in not making those inquiries.”).
23. Spiegel v. Cortese, 196 F.3d 717, 724 n.1 (7th Cir. 1999).
24. See, e.g., BeVier, 806 F.2d at 128 (“A police officer may not close her or his eyes to facts that would help clarify the circumstances of an arrest. Reasonable avenues of investigation must be pursued especially when, as here, it is unclear whether a crime had even taken place.”); Kuehl, 173 F.3d at 650 (citing BeVier, 806 F.2d at 128).
25. Brinegar v. United States, 338 U.S. 160, 174 (1949) (“If those [guilt beyond a reasonable doubt] standards were to be made applicable in determining probable cause for an arrest or for search and seizure…few indeed would be the situations in which an officer…could take effective action.”).
26. Kuehl, 173 F.3d at 650 (“law enforcement officers have a duty to conduct a reasonably thorough investigation prior to arresting a suspect, at least in the absence of exigent circumstances.”).
27. Id. (“probable cause does not exist when a ‘minimal further investigation’ would have exonerated the suspect.”).
28. Houston, supra note 4, at 830 (“A major reason for the development of the some-elements approach was the view that requiring probable cause for each element would frustrate law enforcement even when conducting warranted searches.”).
29. Criss v. Kent, 867 F.2d 259, 263 (6th Cir. 1988) (“A policeman, however, is under no obligation to give any credence to a suspect’s story.”).
30. Maryland v. Pringle, 540 U.S. 366, 372 (2003) (where Pringle was one of three men in the car at 3:16 am, there was $763 of rolled-up cash in the glove compartment directly in front of Pringle, there were five baggies of cocaine accessible to all three men, and the three men failed to offer any information about the ownership of the cocaine or money, “[w]e think it an entirely reasonable inference from these facts that any or all three of the occupants had knowledge of, and exercised dominion and control over, the cocaine.”).
31. Sevigny v. Dicksey, 846 F.2d 953, 958 (4th Cir. 1988).
32. Bigford v. Taylor, 834 F.2d 1213, 1219 (5th Cir. 1988).