The fruit of the poisonous tree is a legal concept referring to how evidence needs to be gathered. If this is done incorrectly, that evidence can then become “poisoned.” This may mean that it cannot be used in court.
For example, say that police officers do not have a search warrant for a property. They go to the property anyway and ask for consent to enter. The homeowner does not provide this consent, and it is clearly not an emergency situation.
Even so, police officers enter the home illegally and find drugs, firearms and other items in the home. They arrest the person who owned that home on this basis.
Is the evidence permissible in court?
But the problem with this arrest is that the police violated the homeowner’s rights by illegally entering their home. They conducted an illegal search, so it means that the evidence may not be permissible in court.
In the hypothetical example above, the only evidence that the police have are the illegal drugs and other such items that they gathered in the search. But they’re not allowed to use that in court because they never should have been in that person‘s house to begin with. As a result, they have nothing and they have to drop the charges, even though they would have otherwise won the case.
This is one example of how the doctrine of the fruit of the poisonous tree could be applied, and it helps to show why it is so critical to understand all of your legal defense options when facing charges.