In a civil suit under Section 1983 this week, Messerschmidt v. Millender, No. 10-704 (February 22, 2012), the United States Supreme Court applied qualified immunity to dimiss claims alleging that officers violated the 4th Amendment by relying on an overly broad search warrant to seize a third-party’s guns and ammunition, which was not evidence of a crime or contraband. The important take away from this case is that officers are entitled to rely in “objective good faith” on the scope of a search warrant signed by a neutral magistrate, with very limited exceptions. That stands to reason because, generally, the officers’ cannot be expected to question the magistrate’s probable cause determination.
The rare exception is when the warrant is based on an affidavit that is so lacking in probable cause as to be “entirely unreasonable,” and obviously so. The Supreme Court took pains to state the exception to the good-faith reliance doctrine does not apply when officers sought to have the warrant approved by their supervisors, the district attorney, and the magistrate.
I attach a link to the case if you would like to read it.