270 F.3d 977 (D.C. Cir. 2001)
United States of America, Appelleev.Mark Stephen Davis, Appellant
No. 00-3050
United States Court of Appeals  FOR THE DISTRICT OF COLUMBIA CIRCUIT
Argued September 5, 2001Decided November 16, 2001

Appeal from the United States District Court  for the District of Columbia (99cr00204-01)
A.J. Kramer, Federal Public Defender, argued the cause  and filed the briefs for appellant.  Gregory L. Poe, Assistant  Federal Public Defender, entered an appearance.
Catherine A. Szilagyi, Assistant U.S. Attorney, argued the  cause for appellee. With her on the brief were Wilma A. Lewis, U.S. Attorney at the time the brief was filed, and John  R. Fisher, Elizabeth Trosman and Neil H. MacBride, Assistant U.S. Attorneys.  Mary-Patrice Brown, Assistant U.S.  Attorney, entered an appearance.
Before:  Randolph, Rogers, and Tatel, Circuit Judges.
Opinion for the Court filed by Circuit Judge Randolph.
Randolph, Circuit Judge:


1
The police stopped Mark Davis  at a roadblock in 1999, arrested him for traffic offenses,  searched him and his automobile, and recovered evidence of  his drug dealing, for which the grand jury indicted him. After the district court denied Davis's motion to suppress, he  entered a conditional plea of guilty to possession with intent  to distribute crack cocaine.  The issue in Davis's appeal is  whether the roadblock complied with the Supreme Court's  interpretation of the Fourth Amendment to the Constitution  in City of Indianapolis v. Edmond, 531 U.S. 32 (2000),  decided after Davis had noted his appeal, and with United  States v. McFayden, 865 F.2d 1306 (D.C. Cir. 1989), on which  the district court relied in denying the motion to suppress.


2
The roadblock had been set up as part of the Metropolitan  Police Department's "Summer Mobile Force."  The evidence  at the suppression hearing consisted of the testimony of one  government witness--a sergeant assigned to this task force-and a sheaf of internal police documents, submitted by the  defense, describing the Summer Mobile Force.  The circumstances of Davis's stop and arrest at the roadblock need not  be recited in detail.  The events occurred early in the evening  in a southwest D.C. neighborhood.  Safety flares lined the  street.  Forty to fifty officers and seven to ten marked police  cars were at the scene.  All vehicles approaching the roadblock were stopped.  Davis pulled over as directed when he  drove up to the checkpoint.  The officers determined that the  car Davis was driving had a forged inspection sticker and that  the temporary registration Davis produced had been altered. After the police arrested him for these and other traffic  violations, they discovered crack cocaine on his person and  drug paraphernalia in his car.


3
The government and the defense agree that if the roadblock complied with the Fourth Amendment, the police acted  constitutionally in stopping Davis (a "seizure") and in arresting and searching him.  The controversy centers on the  roadblock's "primary purpose," as the Supreme Court put it  in Edmond, 531 U.S. at 40-46, or its "principal purpose," as  we put it in McFayden, 865 F.2d at 1312.


4
The Supreme Court has derived a principle from the  Fourth Amendment:  a search or seizure of a person must be  based on individualized suspicion of wrongdoing.  E.g., Terry  v. Ohio, 392 U.S. 1 (1968);  Delaware v. Prouse, 440 U.S. 648,  654-55 (1979);  but see Brown v. Texas, 443 U.S. 47, 51 (1979). As exceptions to this principle, the Court has upheld the  constitutionality of vehicle checkpoints near the border to  intercept illegal aliens (United States v. Martinez-Fuerte, 428  U.S. 543, 556 (1976)), and roadblocks aimed at apprehending  drunk drivers (Michigan Dep't of State Police v. Sitz, 496  U.S. 444, 450 (1990)).  The Court has indicated that roadside  truck weigh-stations and roadblocks to check drivers' licenses  and vehicle registrations would also qualify as exceptions to  the general principle.  Delaware v. Prouse, 440 U.S. at 663 &  n.26;  Edmond, 531 U.S. at 39.  Concerned that its exceptions  would swallow the principle of individualized suspicion, 531  U.S. at 46-47, the Court in Edmond laid down a line:  "When  law enforcement authorities pursue primarily general crime  control purposes at checkpoints ... stops can only be justified by some quantum of individualized suspicion."  Id. at 47. Even if the police check licenses at the roadblock, their  stopping of vehicles would violate the Fourth Amendment  when the "primary purpose of the checkpoint program" is the  "discovery and interdiction of illegal narcotics."  Id. at 46, 34.


5
To the statements from Edmond just quoted, the Court  added this qualifier in a footnote:  "Because petitioners concede that the primary purpose of the Indianapolis checkpoints  is narcotics detection, we need not decide whether the State  may establish a checkpoint program with the primary purpose of checking licenses or driver sobriety and a secondary  purpose of interdicting narcotics."  Id. at 47 n.2.  The footnote seems divorced from the rest of the opinion.  Throughout the text the Court states again and again that when the  "primary purpose" of a roadblock is general crime control it is  unconstitutional.  Id. at 38, 41, 42, 44, 46, 47, 48.  This more  than suggests that if the "primary purpose" had been for a  purpose the Court had already endorsed--such as detecting  drunk drivers, or checking licenses--the roadblock would be  constitutional.  The record in Edmond suggested that enforcement of the drug laws was not simply Indianapolis's  primary reason for establishing the checkpoint program, but  its only reason.  A sign near each of the checkpoints announced:  " 'NARCOTICS CHECKPOINT __ MILE  AHEAD, NARCOTICS K-9 IN USE, BE PREPARED TO  STOP.' "  Id. at 35-36.  If the city's only purpose was  narcotics enforcement, it is hard to explain why the Court  framed the inquiry in terms of its "primary" purpose, unless  the Court believed that it would be constitutional for a State  to "establish a checkpoint program with the primary purpose  of checking licenses or driver sobriety and a secondary purpose of interdicting narcotics."  Id. at 47 n.2.


6
In any event, the question left open by the Edmond  footnote has been answered by our decision in McFayden. Police stopped the defendant in McFayden at a checkpoint  operated in the same manner as the one in this case.  The  defendant, while retrieving his license or registration, took  actions that led the police to narcotics in his car.  865 F.2d at  1309.  Although decided before Edmond, McFayden also  described the issue as whether "the principal purpose of the  roadblock was to regulate vehicular traffic by allowing police  to check drivers' licenses and vehicle registrations."  Id. at  1312.  The court answered yes and found the roadblock  constitutional on this ground, and because it satisfied several  other criteria, even though it "facilitated a narcotics enforcement effort," id. at 1307.  The checkpoint in McFayden was  part of "Operation Cleansweep," a program "designed to  attack the problem of drug dealing in D.C."  Id. at 1308. The police determined where to place roadblocks "on the  basis of community complaints about traffic and narcotics  problems";  citizens in the vicinity of the McFayden roadblock  complained about "speeding automobiles."  Id. at 1308, 1312. In general, "traffic congestion is one serious problem that  results from street drug sales in the District of Columbia." Buyers stop illegally, double-park, make U-turns, speed and  disrupt the flow of traffic in the neighborhood.  Id. at 1308,  1312.  The roadblock in McFayden had a principal purpose of  controlling the traffic problems associated with drug dealing  and "[w]hatever advantage was gained in drug enforcement  was coincidental to the principal purpose of the traffic roadblocks."  Id. at 1313.  While the McFayden court cautioned  (id. at 1312) that it might not sustain a roadblock if it were a  "subterfuge," "purportedly established to check licenses" but  "located and conducted in such a way as to indicate that its  principal purpose was the detection of crimes unrelated to  licensing," it rejected the proposition that a roadblock must  have as its sole purpose the checking of licenses and registrations.  See 4 Wayne R. LaFave, Search and Seizure § 10.8(a),  at 679-80 (3d ed. 1996), and the 2001 supplement thereto at  122-23.


7
Here the district court made several "essential findings" as  Rule 12(e), Fed. R. Crim. P., required.  One of the court's  findings was:  "The roadblock at issue was conducted in a  systematic and nondiscriminatory fashion, for the principal  purpose of vehicular regulation in conjunction with a police  program to increase police presence and to curb drug activity."  Another was that "[t]here is no evidence of subterfuge  in this record."  The court treated the purpose of the roadblock as a question of fact, as did the Supreme Court in  Edmond. 531 U.S. at 40-41.  See also Ferguson v. City of  Charleston, 121 S. Ct. 1281, 1290-91 & n.20 (2001);  Galberth  v. United States, 590 A.2d 990, 1000 n.12 (D.C. 1991).  Factual findings on suppression motions may be set aside only if  clearly erroneous, see, e.g., Ornelas v. United States, 517 U.S.  690, 699 (1996);  United States v. Garrett, 959 F.2d 1005, 1007  (D.C. Cir. 1992);  United States v. Magnum, 100 F.3d 164, 170  n.8 (D.C. Cir. 1996);  United States v. Hill, 131 F.3d 1056,  1059 n.2 (D.C. Cir. 1997).  As in civil cases, the clearly  erroneous standard applies to Rule 12(e) findings based not  only on testimony but also on documents.  See Anderson v.  City of Bessemer City, 470 U.S. 564, 573-76,(1985);  9A Charles Alan Wright & Arthur R. Miller, Federal Practice  and Procedure § 2587 (2d ed. 1995).


8
The district court's findings rested, so far as we can tell, on  the testimony of the government's sole witness.  This officer  said that before setting up the roadblock, the police received  information about "incidents" in the southwest neighborhood  where they arrested Davis.  Community groups and church  "activists" complained about "speeding, children were unable  to play on the sidewalk, parents actually had their children  playing inside the yard because they were afraid a car might  go out of control or their kids might get hit or something." After obtaining this information, and information about  "drugs, gun violence, robberies, [and] assaults," the officer  chose the neighborhood for a "safety compliance check."  The  objective of "safety compliance checks" is not, the officer  testified, simply to stop speeding (as any roadblock doubtless  would), but also to detect "dead tags, dead inspection, no seat  belt, child restraint violations, various traffic violations we  would normally pull someone over in the car."  The officer,  who was in charge of the roadblock, briefed the other officers  "on safety concerns."  He gave no instructions "about looking  for narcotics or firearms," and he was not aware that any of  the officers at the scene were instructed about matters "unrelated to vehicle safety."


9
Regardless whether this evidence would have been sufficient under McFayden--an exceedingly close question--it is  not sufficient under the Supreme Court's intervening decision  in Edmond.  McFayden treated the overall program under  which the roadblock had been established as "immaterial." 865 F.2d at 1312.  But Edmond held that "programmatic  purposes may be relevant to the validity of Fourth Amendment intrusions undertaken pursuant to a general scheme  without individualized suspicion."  531 U.S. at 45-46.  In  determining the principal purpose of the safety checkpoint in  this case, the district court made no findings about the  Summer Mobile Force.  According to a police manual, the  Summer Mobile Force initiative had as its overall objective  "to restore the public's confidence in the Metropolitan Police  Department through the reduction and prevention of crime and violence by utilizing short-term, pro-active, high visibility  enforcement techniques."  Perhaps inspired by the experience of New York City, see George L. Kelling & Catherine  M. Coles, Fixing Broken Windows 108-56 (1996), the department states that it "is committed to building safe, orderly,  and healthy neighborhoods throughout the District of Columbia in partnership with our community."  Among the tactical  approaches mentioned is a "highly trained and supervised  approach to proactive traffic enforcement," using among other things roadblocks, with the goal of reducing "the number  of traffic violations, accidents, and instances of aggressive  driving on our city streets.  Remove the automobile as the  conveyance of choice by narcotics traffickers and individuals  secreting guns and stolen property in the District of Columbia."


10
Since the district court, bound as it was by McFayden,  does not appear to have taken these "programmatic purposes" into account, we must send the case back for further  proceedings in light of Edmond, 531 U.S. at 48, and the  Court's later opinion in Ferguson v. City of Charleston, 121 S.  Ct. at 1291, holding that all evidence must be considered.  We  do not agree with defense counsel that after Edmond the  only thing the district court may consider on remand is the  general purposes of the overall program.  The procedural  posture of Edmond--a suit for an injunction to prevent future  roadblocks for narcotics enforcement and a stipulated record--led the Court to disregard the specific circumstances of  any one roadblock.  Given the very broad objectives of the  Summer Mobile Force initiative, it would be impossible to  discern the purpose of a particular roadblock without determining the reasons behind it.  The record needs clarification  in another respect.  Although we know that citizens in the  neighborhood complained about speeding, it is not entirely  clear whether the only purpose of the police in establishing  the checkpoint was to deal with that problem.  The objectives  of the citizens are not necessarily the objectives of the police. It is also uncertain whether, as in McFayden, open air drug  dealing was causing the traffic problems in this neighborhood. The government had the burden of proof, of course, see United States v. Matlock, 415 U.S. 164, 177 n.14 (1974), but  the absence of such evidence may not be entirely its fault. When the government tried to elicit information of this sort  on redirect, the defense objected.  All that the government's  witness managed to get on the record was his opinion that  there is "[v]ery high traffic" in areas where there is drug  dealing, and his experience that people arrested for drug  offenses are more likely to have "unregistered automobiles,  altered tags, than a regular citizen."  Missing is a link  between the sort of traffic problems mentioned in McFayden  and similar problems stemming from drug trafficking in the  neighborhood where the police located this checkpoint.


11
Several words of caution are in order.  One must be careful  not to fall into the trap of thinking that any "but for" cause of  a roadblock represents its primary purpose within Edmond's  meaning.  Whenever something is done for several reasons, it  might not have been done in the absence of any one of those  reasons.  If there had not been drug dealing in the neighborhood, the McFayden roadblock would not have been placed  there, yet its primary purpose dealt with vehicular safety. The assumption underlying the search for the "primary purpose" is that several purposes might have moved the police to  set up a particular roadblock.  This is why finding the  primary or predominant purpose will often prove difficult, as  the Supreme Court acknowledged in Edmond.  531 U.S. at  46-47.  It is also why findings of the district court, taking  into account all of the available evidence, are entitled to great  respect.


12
One further matter needs to be mentioned.  McFayden  held that a checkpoint, in addition to having a legitimate  primary purpose, must also "promote the state interest in a  'sufficiently productive' fashion."  865 F.2d at 1311-12 (quoting Delaware v. Prouse, 440 U.S. at 660).  The defense  argues that the government failed to satisfy this element. Although the evidence showed that the police issued citations  for 56 moving violations and 30 parking violations, and made  8 traffic arrests, "there was absolutely no evidence of how  many cars in total were stopped;  thus there is no way of  knowing what percentage of the cars stopped were represented by the figures provided by the government."  Brief for  Appellant at 24.  Such statistical evidence is not, however,  essential.  The effectiveness of the checkpoint in fulfilling its  primary purpose may be demonstrated in other ways.  Michigan Dep't of State Police v. Sitz, 496 U.S. at 454-55, a suit to  enjoin future sobriety checkpoints, found the State's program  sufficiently effective not only in light of checkpoint-specific  statistics, but also on the basis of expert testimony showing  the effectiveness of similar checkpoints in other States.  And  in one of the consolidated criminal cases in Martinez-Fuerte  the Court refused to suppress the evidence and affirmed the  conviction despite the absence of any statistics revealing the  number of cars stopped at theborder or the number of illegal  aliens arrested.  428 U.S. at 554, 567.  "While it appears that  fewer illegal aliens are apprehended there" than at other  checkpoints, "it may be assumed that fewer pass by undetected, as every motorist is questioned."  Id. at 554.  To make  the legality of a seizure pursuant to a particular roadblock  wholly dependent on statistics gathered after the roadblock  ended would, in any event, run into the time-honored doctrine  that a search or seizure cannot be justified by its success,  Byars v. United States, 273 U.S. 28, 29 (1927)--or as it is  usually put, by what it turns up, e.g., United States v. Di Re,  332 U.S. 581, 595 (1948);  Wong Sun v. United States, 371  U.S. 471, 484 (1963)--and would ignore that the deterrent  purpose of the exclusionary rule cannot be fulfilled unless the  police can determine ahead of time whether their operation of  a proposed checkpoint will be constitutional.  In short, if the  district court concludes on remand that the primary purpose  of the checkpoint related to vehicular regulation, it may then  rely--as the Supreme Court did in Martinez-Fuerte--on nonstatistical evidence or other considerations in determining  whether the checkpoint furthered that purpose.


13
The case is remanded for further proceedings consistent  with this opinion.


14
So ordered.

