In certain parts of the country police agencies have been using signs announcing nonexistent drug checkpoints to scare drivers into evasive action that the cops cite to justify traffic stops.
Once the driver takes an evasive action, such as making an illegal u-turn, failing to signal, or throwing something out the window, the police officers initiate a traffic stop with the driver.
According to several federal appeals court decisions, these traffic stops may not be legal, depending on how much evidence police have in addition to the apparent evasion of a phony checkpoint.
In the 2002 case United States v. Yousif, the U.S. Court of Appeals for the 8th Circuit deemed a Missouri Highway Patrol scheme that involved stopping every car taking the next exit after signs announcing a drug checkpoint on Interstate 44 to be unconstitutional. Since all cars taking the exit were stopped, the Eighth Circuit Court viewed this fake drug checkpoint as little different from the real drug checkpoint rejected by the Supreme Court in the 2000 case City of Indianapolis v. Edmond.
Local Judge Levitt of Rock Hill Municipal says “In conclusion, sobriety checkpoints are generally upheld if the guidelines established by the line of cases are adhered to. However, drug checkpoints are generally going to be ruled invalid searches and seizures.