Utah vs. Strieff - an illegal detention that ultimately leads to incriminating evidence can still result in the evidence being used against you in certain circumstances
The legal doctrine known as "fruit of the poisonous tree" means that evidence discovered as a result of an illegal act by police generally gets thrown out and can't be used against the persons it incriminates. However, this case dealt with something known as "attenuation." Attenuation is literally defined as something that lessons or mitigates. As applied here it means something done by police that was so removed from the illegal detention that it mitigates the "fruit of the poisonous tree" doctrine and allows the evidence to be used against the defendant.
Strieff was improperly detained by police who saw him leave a suspected drug house. There is no dispute that the detention was illegal. But during the course of the detention it was discovered that Strieff had an active warrant for his arrest. After arresting Strieff the officer searched him, which is normal. During that search drugs and paraphernalia were discovered, and Strieff was charged with these crimes. He moved to suppress, citing the initial illegal detention. The short version is the Supreme Court held that the attenuate circumstances that came between the illegal detention and the legal search were enough to make the search itself, and the items found during the search, admissible. The reasoning is that officers are not likely to routinely detain someone illegally just to attempt to turn it into a legal search.
Situations like this have a lot of little parts that make up the big picture. Anytime a search of you or your property leads to charges against you, contact an attorney immediately. There may be all kinds of defenses that can be used to help your case.