Mackenzie Becker v. United States

The Fourth Amendment permits a search warrant only on probable cause that evidence of a crime will be found at the place to be searched, and this Court has held that the warrant’s supporting affidavit must give the magistrate judge facts from which to make that determination, not merely restate the officer’s own conclusions. In other words, the supporting affidavit must set forth sufficient factual material to establish a probable-cause nexus between the evidence sought and the location to be searched. This case presents a recurring factual scenario: where police have probable cause to believe that a suspect used a gun to commit a crime, and seek a warrant to search his residence for that firearm. The courts of appeals are deeply divided over what is needed to meet the nexus requirement in such circumstances: some hold that it is sufficient, without more, that police have probable cause to believe that the suspect used a gun— on the premise that such weapons are presumptively stored at home; whereas others hold that the supporting affidavit must instead tie the weapon sought to the home to be searched with case-specific facts. As such, the question presented here is: Whether a search warrant’s supporting affidavit establishes probable cause to search a suspect’s home for a firearm used in a crime based solely on the inference that firearms are generally kept at home, or whether the Fourth Amendment requires case-specific facts linking the weapon sought to the residence to be searched.