In the late 1990s, popular, legal, and political concerns were raised across the United States about police harassment of minority groups in their everyday encounters with law enforcement.
These concerns focused on the extent to which police were stopping people on the highways for “driving while black”
(seeWeitzer 2000; Harris 2002; Lundman and Kaufman 2003).
Additional concerns were raised about racial bias in pedestrian stops of citizens by police predicated on “zero-tolerance” policies to control quality-of-life crimes and policing strategies concentrated in minority communities that targeted illegal gun possession and drug trafficking (see Fagan, Zimring, and Kim
1998; Greene 1999; Skolnick and Caplovitz 2001; Fagan and
Davies 2000, 2003; Fagan 2002; Gould and Mastrofski 2004).
These practices prompted angry reactions among minority citizens that widened the breach between different racial/ethnic groups in their trust in the police (Lundman and Kaufman 2003;
Tyler and Huo 2003;Weitzer and Tuch 2002), provoking a crisis of legitimacy with legal, moral, and political dimensions (see
Wang 2001; Russell 2002; Harris 2002).
In an era of declining crime rates, policy debates on policing strategies often pivot on the evaluation of New York City’s policing strategy during the 1990s, a strategy involving aggressive stops and searches of pedestrians for a wide range of crimes
(Eck and Maguire 2000; Skogan and Frydl 2004). The policy was based on the lawful practice of “temporarily detaining, questioning, and, at times, searching civilians on the street”
(Spitzer 1999). The U.S. Supreme Court has ruled police stopand- frisk procedures to be constitutional under certain restrictions
(Terry v. Ohio 1968). The approach of the New York City
Andrew Gelman is Professor, Department of Statistics and Department of Political Science, Columbia University, New York, NY 10027 (E-mail: gelman@stat.columbia.edu). Jeffrey Fagan