The U.S. Constitution provides a variety of procedural guarantees to individuals accused of crimes. The main constitutional provisions regarding criminal procedure can be found in Amendments IV, V, VI, and VO. The Fourth Amendment covers the right to be free from unreasonable searches and arrests. The Fifth Amendment covcrs procedural concerns such as sclf-incrimination and the general right to due process. It requires that the government inform the accused of his or her right to remain silent and that illegally obtained confession must be excluded at trial. The Sixth Amendment addresses the procedures required at trial. It requires that the government provide counsel to defendants unable to pay for it in cases where prison sentences may be imposed. The Sixth Amendment also requires an impartial jury. Finally, the Eihith Amendment states "Excessive bail shall not be required, nor excessive fines imposed, nor cruel and unusual punishments inflicted."

Federal courts must comply with all the criminal procedures listed in the amendments to the Constitution. For state courts, the U.S. Supreme Court has adopted a “selective incorporation" approach to determine precisely what process is due to a criminal defendant Under this approach, only fundamental rights are protected. And the judicial interpretation of fundamental r^hcs has allowed states considerable margin in shaping their own criminal procedures.

Although federal and state legislatures are responsible for their own criminal procedures and procedures can vary from state to state, their procedural rules and statutes are similar in many respects.

That is, the procedure in criminal cases is substantially the same throu^iout the United States. Such fundamental rights as freedom from unreasonable searches and seizures, freedom from cruel and unusual punishment, assistance of counsel, protection against self-incximinadon, a jury trial for prosecutions for cases in which the defendant could be prisoned，and so on are guaranteed in both criminal procedures.

The Fourth Amendment protects suspccts against unreasonable searches and seizures by law-enforcement officers. Generally, a search warrant is required before an officer may search a person or place. (Exceptions are searches consented to by the suspect, safety searches, car searches, searches incident to a lawfUl arrest, and searches in emergencies.)

When an officer seeks a search warrant, the officer must present evidence to a judge or magistrate. The evidence must be sufficient to establish probable cause that evidence of a crime will be found at the place to be searched. If a search warrant is later found to be lacking in probable cause, the evidence seized pursuant to the warrant may be excluded from trial. This can deter police misconduct in searches. Without use of the evidence at trial, the case against the alleged criminal may be dismissed.

When officers have collected evidence pursuant to a search warrant, the burden is on the defendant to show that the warrant lacked probable cause. For a warrantless search, the prosecution bears the burden of proving that the search was reasonable. These arguments are usually heard in a hearing held before trial. And the manner in which the police obtained evidence is almost always an issue.

The general rule is that to make an arrest, the police must obtain an arrest warrant. However, arrests without warrants arc permitted (1) if an officer has probable cause to believe chat a crime has been committed by the person apprehended; (2) when there is no time to obtain a warrant; and (3) when a crime is committed in the presence of an officer. However, the Supreme Court has held that police may not enter a home to arrest its occupant without either a warrant for the arrest or the consent of the owner. Additionally, if an arrest is unsupported by probable cause, evidence obtained pursuant to the invalid arrest may be excluded from trial.

When an anresc is made, the arresting officer must read the Miranda warnings to the arrestee. The Miranda warnings apprise an anrestee of the right to obtain counsel and the right co remain silent. If these warnings arc not read to an arrestee as soon as he or she is taken into custodyf any statements the arrestee makes after the arrest may be cxdudcd from trial.