What is the burden of proving illegal entry?

In the present case defendant made a prima facie showing of illegal entry by establishing that the officers broke into the house without a search warrant, and the burden then rested on the prosecution to introduce evidence that the officers had reasonable cause to break and enter to make an arrest. See Penal Code 844. Since no such evidence was presented, it must be taken as established for the purposes of this proceeding that the entry into the house was unlawful, ¹ [46 Cal.2d 273] and it is immaterial whether or not it was defendant's house. People v. Martin, supra, 45 Cal.2d 755, 290 P.2d 855.