"The magistrate approving the warrant must not be an eager (or sullen) police apparatchik or agent." Justice Appel - State v. Freemont citing Johnson v. United States, 333 U.s. 10 (1948).
On May 2, 2008, the Iowa Supreme Court reversed the felony drug and child endangerment convictions of Guy Fremont and Lacy Nelson because the part-time magistrate that issued the search warrant for their residence was not "neutral and detached" as required by the 4th and 14th Amendments to the United States Constitution.
In State v. Freemont the issuing magistrate, although presented with overwhelming evidence establishing probable cause to search the warrant, improperly authorized the search warrant because he was at the time, also representing the father of the child of Freemont's girlfriend who was living at the residence to be searched, in a pending custody and child support dispute. Obviously his client would benefit from drugs being found in his child's mother's residence and would benefit even more if charges were brought against her. The Court recognized that: "A successful search of the home, which sought to find evidence of drug offenses, could make the position of the mother more difficult in the child custody matter and advance the position of the father. . . . A drug charge in a child custody dispute is a very serious matter and goes to the core of the fundamental question in child custody matters -- the best interests of the child." The court concluded: "Under the unusual circumstances of this case, we conclude that the magistrate had a nonpecuniary personal interest in the matter that objectively cast doubt on his ability to hold the balance, nice, clear and true, between the state and the accused." "The magistrate's simultaneous and conflicting dual roles rendered him unable to meet the requirements of a neutral and detached magistrate under the Fourth Amendment."
While it would seem common sense that the magistrate in this case was not "neutral and detached", decades of prior case law did make the issue a little murky. Justice Appel writing for the Court did a great job of reviewing the prior precedent and clearly enunciating why the magistrate's conflict not only violated the requirement that he be "neutral and detached" but also resulted in a violation of the 4th Amendment and the Due Process Clause of the 14th Amendment. Finally, the Court concluded that the harmless error analysis was not appropriate in these situations because "an invalid warrant is the equivalent of no warrant at all" and thus, the harmless error analysis cannot and does not apply in these situations.
The entire decision can be obtained at: http://www.judicial.state.ia.us/Supreme_Court/Recent_Opinions/20080502/06-1443.pdf