Discuss about the significance of the Exclusionary rule that has been developed to safeguard the protection guaranteed by the Fourth Amendment in the US Constitution.
The exclusionary rule is considered as a legal rule that is used in the US Constitution, which states that any evidence seized by the police illegally against the defendant, such evidence shall not be submitted during the criminal trials. Evidence is permitted to be presented before the court during trials of the criminals. The evidence that are relevant are only admissible in the court, which implies that the evidence must be such that it establishes the existence of any material fact related to the case. The exclusionary rule has been sanctioned to enforce the right of the citizens to be secure in their homes against the any illegitimate governmental interference (Kerr, 2016). However, the rule has been restricting the application of this rule only to evidences that have been obtained illegally by the police. This rule has been considered a deterrent to police misconduct.
The Exclusionary Rule
The exclusionary rule prevents the US government from submitting any evidence in trial that has been obtained illegally in contravention of the Fourth Amendment. The Fourth Amendment ensures protection against illegal seizure and search. The doctrine of exclusionary rule used in the US courts has been sanctioned to deter police and other law enforcement agents from obtaining evidence unreasonably and illegally (Cole, 2015). This rule has been sanctioned in protection of the right of the people to be secured in their homes and to be protected against illegal search and seizures. If an evidence is banned or forbidden from being submitted to the court, it implies that the evidence collected against the defendant cannot be used against him during his trial, provided such evidence has been collected illegally.
Background of the Exclusionary Doctrine
At Common law, the legitimacy of the method to collect evidence had no relevance with the admissibility of such evidence that is, the court was not concerned whether the evidence submitted was obtained legally or illegally neither it formed any issue with respect to the determination of the question. However, in 1886, the Supreme Court paved the way for the establishment of the exclusionary rule in Boyd v United States  116 US 616. In this case, the court held it is important to ensure that a liberal approach should be applied while interpreting the constitutional provisions pertaining to security of person and property (Cole, 2015). The liberal construction principle led to the way establishment of the exclusionary rule that was ultimately brought up in the landmark case of Weeks v United States  232 US 383.
In this landmark case, a US Marshall seized evidence from the home of the defendant without any arrest or search warrant against Mr. Weeks. Moreover, such evidence was seized without the consent of Mr. Weeks, the defendant. The court held that if evidence is seized in this manner and used against the defendant, it should amount to a contravention of the protection guaranteed in the Fourth Amendment; therefore, such evidence shall have no value. The court further reasoned that the Fourth amendment subjects the Federal and US officials to restrictions with respect to the exercise of their authority and power.
Hence, the Court established that the evidence obtained by the Federal agents in a manner that contravenes the Fourth Amendment rights should not be included in the criminal prosecution against the defendant. Further, in Mapp v Ohio  367 US 643, the Supreme Court held that the exclusionary rule is applicable to the states. Furthermore, the decision in Miranda v Arizona  384 U.S. 436 established that the exclusionary rule is applicable to self-incriminatory statements that have been obtained improperly, resulting in contravention of the Fifth Amendment.
The Fourth Amendment and the Exclusion rule
The Fourth Amendment under the US Constitution was enforced with the objective of ensuring security of every person in his or her respective homes. The underlying principle of this amendment is that each man’s castle is his home and every man is safeguarded from arbitrary and illegal police arrests (Kerr, 2016). The Fourth Amendment ensures that no person is subjected to unreasonable seizures and searches of their respective properties by the US government. This Constitutional amendment is based on the law regarding stop-and-frisk, search warrants and any other forms of safety inspections, wiretaps etc. the Fourth Amendment is fundamental to privacy law and other aspects of criminal law.
This legal provision stipulated under the Fourth Amendment aims at safeguarding the privacy right of the people by deterring unnecessary and illegal intrusion from the US Government. In other words, the Fourth Amendment does not ensure safety for search and seizures that the governmental officials carry out legally and on a valid legal ground. Therefore, in order to claim contravention of the Fourth Amendment, the court shall determine whether such intrusion has violated any of the rights of the claimant, where the claimant expected privacy and such intrusion has violated the privacy right.
Significance of the Exclusionary rule
The introduction of the exclusionary rule in the Fourth Amendment has been made to deter police misconduct and enables the courts to exclude admissibility of any incriminating evidence during trial provided the defendant establishes that the evidence was obtained in violation of a constitutional provision (Kerr, 2016). This doctrine permits the defendants to challenge the evidence obtained illegally by initiating a pre-trial motion in order to suppress the evidence.
However, if the court permits the evidence to be submitted during trial and the jury votes in favor of conviction, the defendant is entitled to prefer an appeal to challenge the correctness of the decision taken by the court regarding denial of the motion to suppress. Although the Supreme Court had established in Lockhart v Nelson  488 USS 33 that the defendant is not barred from the retrial, however, if the defendant is convicted in the second trial and the evidence suppressed by the applying the exclusionary rule is crucial to the prosecution.
The doctrine of “Fruit of the Poisonous Tree”
This legal doctrine ‘Fruit of the Poisonous tree’ states that an evidence obtained through illegal search, seizure, interrogation or arrest is not admissible before the court as the evidence is tainted due to the illegal method in which it has been obtained. In other words, this doctrine is considered as a companion to the exclusionary rule, as this doctrine not only excludes evidence from trial that has been obtained in contravention of the Constitution but it also excludes any other evidence that has been obtained through the illegal search or seizure (Kerr, 2016).
For instance, police put a wiretap on a drug-dealer’s phone without obtaining any warrant for the same. Now, the suspect discloses that he has drugs hidden under a dumpster and the buyer picks it from the dumpster. The police finds the place and seize the drugs and such illegal phone calls shall not be admissible to the court which is signified as the ‘poisonous tree’ and the drugs seized as the outcome of the illegal phone call shall not be admissible either as it is signified as ‘the fruit of the poisonous tree’.
Exceptions to the Exclusionary Rule
Although the rationale behind the establishment of the exclusionary rule is to deter the law enforcement officers from conducting illegal searches and seizures contravention of the Fourth amendment, thus, providing remedies to the defendants whose rights have been infringed. However, since this doctrine is a court made rule unlike an independent constitutional right, hence, courts have provided with exceptions to the application of this rule. The exceptions are enumerated as below:
Good faith- if a police officer relies on search warrant and collect evidence but such search warrant turns out to be invalid, under such circumstances, the evidence shall not be excluded from being admissible (Kerr, 2016). This exception as established in the landmark case United States v Leon  104 S Ct. 3405 and in Arizona v Evans  514 US1. Further, in the case Illinois v Krull , the court held that evidence is admissible if the officers rely on nay statute that has been later repealed. Furthermore, in Herring v US , the Court found that the good faith exception should be applicable against the exclusionary rule when the police employees mistakenly failed to maintain warrant database records.
Doctrine of Independent source- any evidence that has been excluded initially for being obtained illegally may be later admissible provided the same evidence has been obtained after lawful seizure or search. This exception was established in the case of Nix v Williams  for the first time and then this rule has been interpreted in Murray v US .
Doctrine of Attenuation – under circumstances where the challenged evidence and the unconstitutional conduct is not directly related and attenuated, the evidence shall become admissible as was established in Utah v Strieff  and Brown v Illinois . The court shall determine three essential factors to apply this exception: presence of interference, temporal proximity and purpose of official misconduct.
Doctrine of Inevitable Discovery – in Nix v Williams it was established that any evidence discovered illegally shall be admissible if it is clear that such evidence would otherwise have been discovered even if the investigations were carried out lawfully.
Evidence admissible for Impeachment- In Harris v New York , the Supreme Court established that this exception shall be used as truth-detecting factor to avert perjury but such evidence shall be admissible only for impeachment and not to establish guilt.
From the above discussion, it can be inferred that the exclusionary rule that has been developed to allow the defendant to suppress certain evidences that are admitted against them on the ground that such evidence has been collected through illegal means and violates their rights guaranteed under the Fourth Amendment. A ‘motion to suppress evidence’ is a request that is made by the defendant before the court to exclude such evidences from the trial proceedings for the illegal manner it has been obtained by the law enforcement officials (Kerr, 2016).
The exclusionary rule has been subjected to limited applications as this rule merely deters the police officers from using illegal means to collect evidence and use it against the defendant, violating the legal provision of the Fourth Amendment and the rights of such defendants. If any police officers or law enforcement officers do not have a search or seizure warrant against any person, the rule prohibits such officers to search or seize any property of such person rendering such search or seizure as well as the evidence obtained through such illegal procedures as invalid and unlawful. The rule though safeguards the rights guaranteed to the people by the Fourth amendment but not the extent that justice cannot be administered.
Arizona v Evans  514 US1
Boyd v United States  116 US 616
Brown v Illinois.  422 U.S. 590
Cole, S. C. (2015). De-Clawing Katz: Emerging Technology and the Exclusionary Rule. SMU Sci. & Tech. L. Rev., 18, 47.
Harris v New York . 401 U.S. 222
Herring v US (2009) 555 U.S. 135
Illinois v Krull (1987) 480 U.S. 340,
Kerr, O. S. (2016). The Effect of Legislation on Fourth Amendment Protection. Mich. L. Rev., 115, 1117.
Lockhart v Nelson  488 USS 33
Mapp v Ohio 367 US 643
Miranda v Arizona  384 U.S. 436
Murray v US (1988) 487 U.S. 533
Nix v Williams (1984),467 U.S. 431
United States v Leon  104 S Ct. 3405
Utah v Strieff (2016) 579 U.S. ___, 136 S. Ct. 2056
Weeks v United States  232 US 383