Cynthia Lee (George Washington University Law School) has posted Probable Cause with Teeth on SSRN. Here is the abstract:

Recent incidents involving African Americans who were arrested by police for engaging in activities that rarely lead to police intervention when individuals who are not African American engage in similar activities highlight the need for clarity regarding how much certainty of guilt is required before an officer can arrest an individual. The Supreme Court, however, has provided very little guidance on exactly how much certainty of guilt is required to establish probable cause, stating only that probable cause is more than a mere suspicion but less than proof needed to convict. In 1983, Justice Rehnquist lowered the bar significantly when he opined in Texas v. Brown that probable cause “does not demand any showing that such a belief be correct or more likely true than false.” Many lower courts have repeated Justice Rehnquist’s comment on probable cause as if it were settled law. In doing so, very few seem to recognize that Texas v. Brown was just a plurality opinion and the meaning of probable cause was not the main issue before the Court.

 
This Article argues that Justice Rehnquist’s musings on the meaning of probable cause in Texas v. Brown should not be followed for several reasons. First, thirty-five years ago, Justice Rehnquist was only able to get three other Justices to sign onto his opinion. Texas v. Brown was just a plurality opinion, and his statement on the showing required for a finding of probable cause was not necessary to the judgment. More importantly, a majority of the Court has never repeated Justice Rehnquist’s statement that probable cause means something less than the preponderance of the evidence standard required in civil cases. Second, Justice Rehnquist’s view of probable cause is wrong as a matter of history, precedent, and logic. Third, Justice Rehnquist’s view of probable cause allows for, and perhaps even encourages, racial disparity in arrests. A more robust showing should be required for a finding of probable cause.