What doctrine permits the admission of illegally obtained evidence?

The inevitable discovery doctrine allows for the admission of illegally obtained evidence if the prosecution can prove that the evidence would have inevitably been discovered through lawful means. This doctrine is based on the rationale that excluding the evidence would not serve the goal of discouraging police misconduct when there is no reasonable expectation that the evidence would have been concealed from lawful investigation in the absence of the illegal conduct.

For instance, if law enforcement officers conduct an illegal search but could have legally discovered the same evidence through a separate, lawful investigation, this doctrine justifies the admission of that evidence in court. It serves as a safeguard to ensure that the judicial process can still function effectively even when there are instances of police misconduct, provided that the evidence in question is unavoidable through standard investigative procedures.

This differs from other doctrines such as "fruit of the poisonous tree," which suggests that evidence obtained through illegal means must be excluded, and "attenuation," which deals with the eventual distancing of evidence from the initial illegal action. The "independent source" doctrine also allows for the admission of evidence if it was obtained independently from the illegal source, but is distinct from the inevitability concept.