In Pearson v. Callahan, No. 07-751, the U.S. Supreme Court will consider what circumstances justify a warrantless search under the Fourth Amendment to the U.S. Constitution.
Afton D. Callahan invited a police informant into his trailer home for the purpose of selling him methamphetamine. When the sale was completed, the informant notified police by wire and they immediately searched the trailer without a warrant. A Utah state court convicted Callahan of possession and distribution; but the state appeals court reversed, finding a violation of Callahan’s Fourth Amendment protection against unlawful search and seizure. Callahan then sued the police officers for damages.
My view is that allowing a warrantless search whenever someone invited into a home sees a crime would gut the Fourth Amendment protection against illegal searches and seizures. People do not consent to a blanket waiver of their right to a search warrant every time an invited guest or tradesman passes through their door.
A better rule is that a knowing and intelligent waiver of Fourth Amendment rights occurs only when a person authorized to admit others into their home either does so for an illegal purpose like a narcotics transaction or prostitution; or opens the door to the general public.
This Fourth Amendment interpretation is akin to the principle in civil law that you must do equity to receive equity.
Furthermore, if you are participating in a crime and something illegal is within line of sight and risks disappearing before police can obtain a warrant – and a warrant would likely be issued if law enforcement took the time to obtain one – then it seems reasonable to permit proceeding without one. By comparison, when a traffic stop is supported by probable cause, this same approach permits peering into the glove box for the protection of the arresting officer. Potentially disappearing contraband in a criminal context — and possibly injured officers — are exigent circumstances that should in my opinion justify an exception to the requirement of a warrant.
The open-invitation-to-the-public prong of my warrant exception calls for more explanation: A broker’s open house tour group would not be the general public, because the invitation was limited to real estate brokers and agents. An undercover officer could not lawfully join that tour and signal for a warrantless search from inside the home. In contrast, a Sunday afternoon open house advertised in the local paper would be different, as that would be open to anyone.
The attractiveness of my proposal is that it resolves the Fourth Amendment issue at the front door with simple, clearly defined criteria. If the person opening the door is permitted to let people in, and allows someone to enter for a criminal purpose or in total disregard of the visitor’s identity – then their right to a search warrant should be deemed waived.
 Being a family lawyer facilitates my “thinking outside the box” which in this case is built out of prior Fourth Amendment case law.