An arrest warrant is a written order from a judge or magistrate that commands the police or other authority to physically take a person accused of a criminal offense into custody. The Fourth Amendment to the United States Constitution requires an arrest warrant to be supported by probable cause—which means there is a reasonable basis to believe the person to be arrested committed a crime.

Arrest warrants protect people from unlawful arrests by requiring the independent review of supporting facts by a person (judge or magistrate) who is not involved in the process of investigating the alleged crime. Arrest warrants also give the accused actual notice of the charge of a criminal offense committed by the accused. Arrest warrants are generally required to take an accused into physical custody unless there is an exception to the warrant requirement—such as when the crime is committed in the presence of the arresting officer.

In New York, as in other states, an arrest warrant is a legal document issued by a judge or magistrate that authorizes law enforcement to take a person into custody on suspicion of a crime. The requirement for an arrest warrant is grounded in the Fourth Amendment of the U.S. Constitution, which mandates that warrants be supported by probable cause. This means there must be a reasonable basis, typically established through sworn statements or affidavits, for believing that the individual has committed a crime. The process ensures that arrests are not made arbitrarily, as the warrant application is reviewed by a judicial officer who is not involved in the investigation. While arrest warrants are a common requirement for taking someone into custody, there are exceptions where a warrant is not needed, such as when a crime is witnessed by a police officer. In such cases, an officer may make an arrest without a warrant. New York law conforms to these constitutional principles and provides specific procedures for the issuance and execution of arrest warrants.