Sergeant Marvin Bonnstetter of the Chicago Police Department was investigating gangs in Chicago. While he was at the jail he was approached by a man who claimed to have information. Together with an FBI officer he met with this man (known as John Doe). The officers asked the man a number of questions. He seemed knowledgeable about Chicago gangs and he was able to identify pictures of gang members.

John Doe told the officers that he had seen a convicted felon, Ruben Estrada coming out of his residence, located at 1536 West Walton in Chicago, with a gun. Doe told the officers that the West Walton address was a single family residence. The officers and Doe drove by the building and it appeared to be a single family residence. There was a real estate sign in the window and the officers thought it was a home run business.

Bonnstetter used the information to write an affidavit and submit it to the court to get a search warrant for the residence. A magistrate signed the search warrant.

Fourteen police officers and FBI agents, including Bonnstetter went to the residence to serve the search warrant. Shortly after arriving they discovered that it was not a single family residence. The real estate office was separate from the rest of the building and their were two residential apartments in the building. Furthermore no one by the name of Ruben Estrada lived in the building. They searched the upstairs apartment where Maira Guzmen, a pregnant woman, her husband, and their nine year old son lived.

The Seventh Circuit found that while Bonnstetter acted appropriately in obtaining the search warrant the police did not properly execute the warrant. The court citing Maryland v. Garrison stated that since the officers realized that it was not a single family residence prior to the search, they were required to withdraw.