California police officers improperly arrested Watson in his apartment. Before taking Watson to the police station, arrangements had to be made for the care of Watson's cat and dog. In an attempt to provide for the care of these animals, the officers went to the apartment of a neighbor (Mrs. Lopez) to inquire if she would take care of the animals. Mrs. Lopez told the officers that they should investigate Watson for a recent bank robbery in which the robber had presented his demand in a note threatening that he had nitroglycerin on his person.
Mrs. Lopez stated that she was in Watson's apartment on the morning of the robbery and he was writing a note and had asked her how to spell nitroglycerin. The officers had not suspected Watson of the robbery, but the investigation that followed produced sufficient evidence to convict Watson of the bank robbery. An appeal was taken from the conviction arguing, among other issues, that the defense position of "the fruit of the poisonous tree" doctrine required suppression of the evidence that was ultimately used to convict Watson.