Final answer:
Courts evaluate the use of intrusive police techniques based on exceptions like 'good faith', 'inevitable discovery', and national security needs. The 'fruit of the poisonous tree' doctrine renders evidence from unlawful searches inadmissible.
Proper procedural safeguards, as mandated by Miranda, are essential for evidence obtained during custodial interrogation to be admissible.
Step-by-step explanation:
Factors Determining the Use of Intrusive Police Techniques
The courts decide on the admissibility of evidence obtained through intrusive police techniques based on various established precedents and exceptions to the Fourth Amendment’s requirement for a search warrant.
Certain exceptions permit evidence to be used even if obtained without following legal procedures, such as the “good faith” exception and the “inevitable discovery” exception. Another is when surveillance is directed against foreign powers for national security purposes as highlighted in In re Directives.
However, not everything discovered during illegal searches can be used as evidence. The “fruit of the poisonous tree” doctrine specifies that evidence obtained as a direct result of an unlawful search or seizure is inadmissible. The courts also make allowances for situations where police may stop and frisk a person based on reasonable suspicion according to Terry v. Ohio.
Moreover, the Miranda ruling emphasizes the importance of procedural safeguards during custodial interrogations to secure the privilege against self-incrimination.
While courts may look favorably upon obtaining a search warrant, they scrutinize the conditions under which warrantless searches and seizures occur. There are situations where the police are expected to inform individuals of their right to counsel and protection against self-incrimination as per the Fifth Amendment, otherwise, the evidence obtained could be deemed inadmissible.