1. The Exclusionary Rule:
The principle based on federal Constitutional Law that evidence illegally seized by law enforcement officers in violation of a suspect's right to be free from unreasonable searches and seizures cannot be used against the suspect in a criminal prosecution.
The exclusionary rule is designed to exclude evidence obtained in violation of a criminal defendant's Fourth Amendment rights. The Fourth Amendment protects against unreasonable searches and seizures by law enforcement personnel. If the search of a criminal suspect is unreasonable, the evidence obtained in the search will be excluded from trial.
2. Voluntariness of Statements:
If a statement is beaten out of a suspect, or if he was coerced into confessing under the duress of a threatened beating, lynching, or other violence, the confession was tainted. Some of the circumstances that will invalidate confession are:
i. Brutality or threatened brutality
Promises to drop the charges or to forgo prosecution of other suspected crimes
Threats to arrest members of the suspect’s employer and him fired if he does not cooperate
Threats to arrest members of the family or to cut off welfare assistance from them
Holding the suspect on false charges
Refusing the suspect the right to make bail
Using false or illegally seized evidence to induce a confession
3. The Miranda Warnings:
The Miranda Warning is a police warning which is given to criminal suspects who are in the custody of law enforcement in the United States before they can ask questions regarding what took place during the crime.
Law enforcement can only ask for specific information such as name, date of birth and address without having to read the suspects their Miranda warnings. Confessions and other information that you provide them will not make up admissible evidence unless you have been made aware of and waived your "Miranda rights".
The Miranda warnings