In United States v. Green, 111 F.3d 515 (7th cir. 1995), police officers illegally stopped the defendant's vehicle.
During the course of the stop, the officers discovered that a passenger in the vehicle was wanted on an outstanding warrant.
The officers arrested the passenger and searched the vehicle incident to arrest. The officers discovered controlled dangerous substances and a gun. They then arrested the driver.
The driver moved to suppress the drugs and gun. The Seventh Circuit held that the lawful arrest on an outstanding warrant constituted an intervening circumstance that dissipated any taint caused by the initial illegal stop. 111 F.3d at 522.
In comparison to other instances in which the Supreme Court has permitted the admission of evidence acquired after an unlawful action, "where a lawful arrest pursuant to a warrant constitutes the 'intervening circumstance,' it is an even more compelling case for the conclusion that the taint of the original illegality is dissipated." Id. at 522.
Indeed, according to the court, "it would be startling to suggest that because the police illegally stopped an automobile, they cannot arrest an occupant who is found to be wanted on a warrant." Id. at 521.