What doctrine extends the exclusionary rule to evidence obtained indirectly as a result of unconstitutional police behavior?

The Fruits of the Poisonous Tree Doctrine is the correct answer because it establishes that not only is evidence obtained through unconstitutional means, such as an illegal search or seizure, inadmissible in court, but also any evidence that is derived from that initial tainted evidence. This doctrine emphasizes the principle that if the source of the evidence, or the "tree," is contaminated, then anything gained from it, or the "fruit," is likewise considered inadmissible. This extension helps to deter law enforcement from violating constitutional rights by ensuring that they cannot benefit from illegal actions.

In contrast, the Due Process Clause pertains to the legal requirement that the state must respect all legal rights owed to a person, but it does not specifically address the exclusion of evidence. The Necessary Evidence Doctrine does not exist under formal policy or legal standards that directly correlate to the exclusionary rules. The Chain of Custody Principle focuses on maintaining the integrity of evidence during its handling, which is essential for admissibility, but it does not relate to the origins of how that evidence was obtained in relation to constitutional violations.