Criminal Procedure: Basic Fourth Amendment Principles & the Exclusionary Rule

When government violates the Fourth Amendment, illegally obtained evidence is excluded from court use.
This places parties in the same legal position as if no illegal seizure occurred.
The remedy primarily assists the guilty, not directly the innocent.

Before 1914, illegally seized evidence was rarely excluded from federal trials.
Weeks v. United States, 232 U.S. 383 (1914): Established the exclusionary rule, prohibiting admission of illegally obtained evidence in federal trials to deter federal police misconduct.

Allegations of Fourth Amendment violations lead to adversarial hearings (often pretrial).
A judge determines whether to suppress or admit contested evidence.

Prevents courts from condoning or becoming indirect participants in Fourth Amendment violations.
Deters future law enforcement misconduct by limiting the utility of illegally seized evidence.

Initially, the Weeks exclusionary rule did not apply to state courts or police.
Silver Platter Doctrine: Allowed evidence illegally seized by federal officials to be admissible in state courts, and by state officials in federal courts.
Elkins v. United States, 364 U.S. 206 (1960): Abolished part of the doctrine, requiring evidence illegally obtained by state police to be excluded from federal courts.

Mapp v. Ohio, 367 U.S. 643 (1961): Incorporated the Fourth Amendment and the exclusionary rule to the states via the Fourteenth Amendment's Due Process Clause.
- Facts: Police conducted a warrantless search, using evidence found against Mapp in state court. She argued Fourth Amendment protection.
- Held: Yes, the Fourth Amendment and exclusionary rule apply to states; due process requires fundamental fairness, and the right to privacy must be enforceable against state action.

"Fruit of the Poisonous Tree Doctrine": Excludes evidence obtained by exploiting a Fourth Amendment violation.
Wong Sun v. United States, 371 U.S. 471 (1963): Extended the rule to derivative evidence discovered as a result of an illegal search, which would not have been found but for the initial illegality.

Exceptions apply when the deterrent effect on police behavior is marginal or non-existent.
Independent Source Rule: Illegally seized evidence is admissible if obtained from a separate, lawful, and untainted source.
Rule of Inevitable Discovery: Evidence discovered through illegal means is admissible if a separate, legal means of discovery would have inevitably led to the same evidence.
Doctrine of Attenuation: Illegally seized evidence is admissible if sufficiently separated by time, distance, and/or intervening events from the original illegality, thereby purging the "poison."
Good Faith Exception: Applies when police make understandable, good-faith errors (e.g., relying on a defective warrant issued by a judge) where applying the exclusionary rule would not deter future police misconduct.

Parole Revocation Hearings: No application where social costs outweigh minimal deterrent benefits (Pennsylvania v. Scott, 524 U.S. 357 (1998)).
Other Contexts: No vicarious assertion, no application to police reliance on a law later declared unconstitutional, not used to impeach a defendant or witness, and does not apply to judicial errors.

Bivens v. Six Unknown Named Agents, 403 U.S. 388 (1971): A civil damage suit against federal agents for personal conduct violating constitutional rights, offering a remedy when the exclusionary rule doesn't apply (e.g., for victims of illegal searches who are never tried).

Standing: Requires a party to have personally had their Fourth Amendment rights violated by police concerning their person, property, or private spaces (e.g., house, car, digital devices).
It is a threshold issue: only if standing exists can arguments for evidence suppression proceed.
Rakas v. Illinois, 439 U.S. 128 (1978): Defendant lacked standing to contest a search of another's car because he had no personal claim to the car or its contents.
Brendlin v. California, 551 U.S. 249 (2007): Expanded standing, granting a passenger standing to contest the stop of a vehicle, as passengers are also considered "seized" under the Fourth Amendment when the driver is stopped.
Vicarious Standing Not Permitted: Requires a personal Fourth Amendment violation; no standing for briefly using another's apartment for illegal activity, or in a stolen car.