The Fourth Amendment of the United States Constitution guarantees the right to be secure against unreasonable searches and seizures. It provides that warrants for an arrest or for a search shall be based on probable cause, shall be supported by an oath or an affirmation, and shall describe with particularity the place to be searched or the person or thing to be seized.
An arrest occurs when a person is placed under restraint or is taken into custody by a police officer. A person is placed under restraint when his or her freedom of movement is restricted by physical force or by a show of authority. Physical force occurs with the slightest touching or application of physical force. A show of authority occurs when a police officer's words and actions operate as a command. If a person is free to leave or believes that he or she is free to leave, an arrest has not occurred. Mere questioning by a police officer does not constitute an arrest.
An arrest warrant is a written order from a magistrate or other judicial officer to a police officer commanding the seizure of a person. The magistrate or the other judicial officer must be neutral and detached, that is, not involved in the arrest. Prior to issuing the arrest warrant, the magistrate or the other judicial officer must determine whether there is probable cause for an arrest. Probable cause for an arrest warrant requires a showing that a person has committed a crime or is in the process of committing a crime. The arrest warrant may be based upon a sworn affidavit or upon a complaint. The affidavit or the complaint must provide a sufficient basis for an independent determination of probable cause by the magistrate or the other judicial officer.
The arrest warrant must contain the following:
When a police officer is authorized under an arrest warrant to enter a private dwelling, the officer must comply with the "knock and announce" rule. The officer must announce his or her authority and purpose before entering the private dwelling. The officer may force his or her way into the private dwelling only if he or she is denied entry. However, there are exceptions to the "knock and announce" rule.
An arrest warrant may be issued along with a search warrant. The police may not exceed the scope of the arrest warrant or the search warrant. If the police exceed the scope of the search warrant, the seized evidence may be suppressed and may not be able to be used at trial.
An accused may attack his or her arrest under an arrest warrant by claiming that the arrest warrant was invalid. If the arrest warrant is valid on its face, that is, if it contains the requirements set forth above, the accused must show that the affidavit or the complaint on which the arrest warrant was based lacked a showing of probable cause and that the arrest warrant was not based on probable cause.