Academic journal article Law and Contemporary Problems


Academic journal article Law and Contemporary Problems


Article excerpt

The title of this symposium, "The Death of Probable Cause," overstates the case, for "probable cause" is, of course, not dead. (1) Nor is this fundamental legal concept ever likely to pass entirely from the constitutional scene. (Perhaps a better title would therefore add a question mark: "The Death of Probable Cause?") But probable cause is on the ropes. Its scope of application is narrowing, its meaning mutating, its competitors thriving, starving it of resources. (2) Why is this so? Is it a good or a bad thing for the health of the republic?") What does it, and, equally importantly, what should it, mean for the future of the Fourth Amendment and its statutory progeny? These are the questions this symposium seeks to answer.



But no answer can be forthcoming without first understanding just what probable cause is. The concept of "probable cause" has four components: (1) one quantitative--how convinced must the fact finder be? (2) one qualitative--how trustworthy must be the evidence upon which the judgment is made? (3) one moral--is the evidence sufficiently individualized? and (4) one temporal--when must the judgment be made? The meaning of each of these components has been changing, a change accelerating in the past few years.

A. The Quantitative Component

Although it is hard to describe standards of proof like that embodied in the phrase "probable cause" in purely mathematical terms, (3) judges and scholars have long found rough mathematical approximations of the standard useful. Thus, for several decades, most judges understood probable cause's quantitative requirement to hover around a preponderance of the evidence, usually falling slightly under fifty-percent confidence that a particular person did the crime or that evidence of crime would be found in a specific location. (4) Surveys of judges confirmed this fact, (5) leading scholars like Wayne LaFave found it to be consistently evidenced in lower-court opinions, (6) and the United States Supreme Court's admittedly vague definition of the term fostered this understanding. (7)

No more. Just two terms ago, the high Court decided a case, Maryland v. Pringle, (8) widely (though not universally) interpreted as meaning that probable cause's quantitative requirement has now fallen, at least in some instances, to about thirty-three percent, rather than just under a fifty-percent, confidence level. (9) Alternatively, Pringle might mean that probable cause has no fixed quantitative meaning, its meaning instead changing based upon circumstances, a meaning that can, however, fall to a level so low as to be equivalent to what used to be considered the hallmark of the less-muscular concept of "reasonable suspicion," that is, about a one-third likelihood of guilt. (10)

If this latter interpretation is correct, however, the Court has given no guidance for determining when the standard of proof should be lowered. The judgment for now seems to be left to the discretion of lower courts and law enforcement, both of whom generally avoid expressly confronting what

standard of proof they are using anyway. (11) Furthermore, if the quantitative requirement for probable cause has been lowered, at least in some cases, then surely the quantitative requirement for reasonable suspicion has also been lowered. Moreover, if that requirement can rise and fall based upon circumstances for both concepts, then what, exactly, is it that distinguishes "probable cause" from "reasonable suspicion" in the first place? In any event, lower courts and commentators seem to be finding in Pringle a signal that their degree of confidence in suspecting crime before searching or seizing can decline with no retribution likely from the Supreme Court. (12)

B. The Qualitative Requirement

The high Court has also long made it clear that probable cause cannot be based on mere hunches or suspicions. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.