A sheriff department officer serves a warrant by informing the defendant named in the warrant of the officer's authority, the officer's intention to arrest the defendant, the cause of the arrest, and that the warrant exists, according to Montana Code Annotated 46-6-216. These steps do not apply if the defendant flees or resists arrest. The arresting officer does not need to have possession of the warrant, but must show it to the defendant as soon as practical if requested.
A judge issues a warrant if a complaint or an affidavit filed with a complaint provides probable cause that the defendant committed the offense, describes LawFirms.com. A judge gives a law enforcement officer the authorization to arrest a person by issuing an arrest warrant, and law enforcement officers or prosecutors typically request arrest warrants if the crime was not witnessed by a law enforcement officer. The judge needs any information pertinent to the case or evidence when a law enforcement officer or prosecutor requests an arrest warrant. Law enforcement officers or prosecutor typically present the judge with at least two pieces of evidence when they request an arrest warrant.
A warrant contains three elements. It must contain the defendant's name, the offense the defendant is charged with by the complaint and name the issuing court, according to Lawyers.com.