There are many legal doctrines that, while they may not be official laws or rules, are still general principles that are usually followed. One of these doctrines is known as the fruit of the poisonous tree. It is sometimes applied in criminal cases.
The general idea behind this doctrine is simply that every step the police take needs to follow the law and the regulations that are placed upon them. If they break these regulations, they can violate someone’s rights by acting in an illegal manner, despite being the authorities themselves. When this happens and it leads to a chance for them to obtain evidence, then that evidence may be thrown out of court.
An illegal search
An example of this is when the police conduct an illegal search of your home. Say that they arrive at your house and they do not have a warrant. They ask to come inside, but you refuse to give your consent.
Undeterred, the police force their way into your house and they find evidence of criminal activity. They take that evidence and they arrest you, assuming that it is a slam dunk case where it is obvious that you are guilty. But even if that evidence is compelling, the fact that they illegally obtained it after violating your rights under the Fourth Amendment means that the evidence may not be permitted in court. This would make a conviction very unlikely if that’s the only evidence that the police have.
As such, you can see just how important this doctrine may be to your case. Be sure you know about all the legal steps you can take and the options you have.