Is the DC Checkpoint Plan Unconstitutional?
The Washington Post has a detailed story on DC's plans for a "military style checkpoint" to stop gun violence. Eugene mentioned it briefly below, but I wanted to blog at some length about the legal issues. It turns out that there's a fairly specific Fourth Amendment law of automobile checkpoints, and that we can look to those cases to see how the DC law fits in. My bottom line: I think the DC checkpoint plan is pretty clearly unconstitutional.

  Let's start with some background. The Supreme Court has held that the legality of automobile checkpoints are governed by a reasonableness standard under the Fourth Amendment. The cases try to balance the government's interests against the privacy interest and permit the automotive checkpoint when the government has a good reason and the infringement on privacy is minimal. So, for example, the police can use a drunk driving check point, or an immigration checkpoint, so long as they are well designed to minimize the privacy intrusion. See, e.g., Michigan Dept. of State Police v. Sitz, 496 U.S. 444 (1990) (drunk driving checkpoint okay); United States v. Martinez-Fuerte, 428 U.S. 543 (1976) (immigration checkpoint okay)

  In 1996, in Maxwell v. City of New York, 102 F.3d 664 (2d Cir. 1996), a divided panel of the Second Circuit relied on these precedents to uphold a checkpoint nearly identical to the one that DC is planning. The Second Circuit thought that the checkpoint was reasonable for three reasons:
First, the checkpoints in question served an important public concern in attempting to deter drive-by shootings that were, or were reasonably perceived to have been, connected with widespread drive-up drug purchases. Second, at the time of implementation, the checkpoints were reasonably viewed as an effective mechanism to deter criminal behavior in the barricaded area. Indeed, checkpoints similar to the one here had been effectively used in the past by the New York City Police. Third, the intended level of intrusion to motorists was minimal. No vehicle was to be stopped or its operation questioned unless entry into the cordoned-off area was desired. For those seeking entry, the stop was meant to be brief and was aimed solely at ascertaining the motorists' connection to the neighborhood.
  The Post story suggests that DC is relying on the Maxwell case as authority for legality of the checkpoint. And if the law were today what it was in 1996, I would say their legal case is certainly plausible.

  The difficulty is that four years after Maxwell, the Supreme Court took a different turn in its cases in City of Indianapolis v. Edmond, 531 U.S. 32 (2000). In Edmond, the City of Indianapolis set up vecicle checkpoints to search for drugs. The city was worried that people were bringing narcotics into the city, and they figured that they could set up reasonable checkpoints to deal with the drug problem much like the earlier checkpoints had dealt with the problems of drunk driving and immigration. The Supreme Court disagreed, concluding that the check points were unconstitutional because the government interest was a traditional law enforcement interest rather than something else like public safety.