• The magistrate decides whether or not to issue a warrant.Police image by Zeno from Fotolia.com
  
  For a police officer to arrest a person in his own home or to search property, the officer must obtain a warrant. However, a police officer cannot just produce a warrant on his own. The officer must follow certain steps, and the first step is applying for a warrant from a magistrate judge. If the judge decides to grant a warrant, the police officer must still continue to follow procedure when executing the warrant.
  
  

Affidavit

• A police officer must prepare a written affidavit stating the facts giving rise to probable cause to issue a warrant. A police officer has probable cause when knowledge of certain circumstances and facts that would be sufficient for a reasonable person to believe that an item subject to a search would be found in a particular location at a specified time or that a person can be found in a particular location. For a search warrant, the affidavit addresses the item and/or place to search. For an arrest warrant, the affidavit identifies the person to arrest.
  
  

Neutral and Detached Magistrate

• A neutral and detached magistrate must review the affidavit to determine if the police officer has set forth sufficient probable cause; it includes a specific description of the item or person sought; and it includes a statement of when, where, and how the warrant will be executed. The requesting officer must also make an oath or affirmation to the magistrate that the contents of the warrant are accurate. The magistrate must not have participated in the investigation and may not serve as a "rubber stamp" of a warrant request; nor should a magistrate be paid for each warrant issued. The magistrate may, however, question the police officer to gain adequate knowledge before deciding on whether or not to issue a warrant. The magistrate must make his determination of whether or not to issue a warrant independent of the police officer's wishes.
  
  

Execution of a Search Warrant

• When a police officer obtains a search warrant, the officer can then conduct the search pursuant to the warrant's terms and subject to the warrant's scope. For the search and seizure of an item to be valid, the officer can only search in places where the item sought can be found. For example, if the police officer is searching for a machine gun, he cannot look for it in an ashtray under cigarette ashes. If he does take it upon himself to search the ashtray and finds marijuana, that evidence is the fruit of an illegal search and, therefore, inadmissible.
  
  

Execution of Arrest Warrant

• A police officer must obtain an arrest warrant to arrest a suspect within a dwelling. Once the police officer obtains the arrest warrant, he can only enter the dwelling specified by the warrant and only arrest the suspect named. If he enters the dwelling and finds not only the suspect but also another person of interest, he cannot arrest that other person.