A previous blog post discussed legal defenses to a child pornography offense in Pennsylvania. Defendants may avoid conviction if they accidentally viewed the prohibited material, if they possessed the material for a bona fide educational, scientific, governmental or judicial purpose or if the alleged victim was over the age of 18. The laws of criminal procedure, such as the exclusionary rule, apply to criminal defendants facing child pornography as well as other criminal charges.
The exclusionary rule and the related "fruit of the poisonous tree doctrine" were designed to deter police misconduct and ensure compliance with the Fourth Amendment protections against unreasonable search and seizure. The exclusionary rule was established when the Supreme Court of the United States ruled in Weeks v. United States that defendants may not be convicted based on evidence seized without constitutional justification. The fruit of the poisonous tree doctrine additionally allows any evidence that was obtained from an illegal search to be excluded from trial.
Under the fruit of the poisonous tree doctrine, courts may exclude evidence obtained as a result of an illegal search. Therefore, if a defendant confesses after evidence against him was unlawfully obtained, that confession may be excluded from trial. However, unlawfully obtained evidence is not automatically excluded. Rather, defendants must ask the court to suppress any evidence they believe was wrongfully seized by filing a pre-trial motion to suppress the evidence.
If a defendant is convicted based on wrongfully obtained evidence, the defendant may file a motion to suppress on appeal. The evidence may then be suppressed at the defendant's retrial.
The exclusionary rule and the fruit of the poisonous tree doctrine can therefore be important elements of a defendant's criminal defense strategy if he or she was arrested or convicted based on evidence seized in violation of the Fourth Amendment.