In Steagald v. U.S., 451 U.S. 204 (1981), the Supreme Court held that police may not use an arrest warrant to enter a third party's home in order to find and arrest the person named in that warrant. See id., 421 U.S. at 222. Before crossing the threshold, police must get a search warrant authorizing them to look inside that home for that suspect. See id. A contrary rule would effectively subject any home where a fugitive named in an arrest warrant might be located to a warrantless entry and search. See id., 421 U.S. at 215-16. In these circumstances, therefore, an arrest warrant cannot be substituted for a search warrant because it does not protect privacy interests in the home. See id., 451 U.S. 204, 213-14.