The way researchers have traditionally measured police action limits t
heir capacity to test legal theories and shed light onto the determina
nts of law at the initial stage of the criminal justice process. This
paper describes extant police action measures and their limitations, o
ffers a new measure that taps variation in the amount of law police of
ficers use in encounters with citizens, presents the results of an ana
lysis that utilizes the new measure, and discusses the implications of
this new measure for legal research.