In People v. Elder (1976) 63 Cal.App.3d 731, the Court upheld an entry to execute a search warrant for evidence of a bookmaking operation under circumstances similar to those in the present case. The officer, who knew that people were in the house, waited 20 seconds without receiving any response and then entered the residence. The court stated as follows: "An unreasonable delay in responding to the officer constitutes refused admittance. Marwin waited 20 seconds before entering because he was attempting to comply with the law and apparently it was either his general rule, or the general rule of his department, to wait 20 seconds to allow time to respond to a knock on a door . . . . Silence for 20 seconds where it is known that someone is within the residence suggests that no one intends to answer the door. Twenty seconds of silence may be sufficient in one case and insufficient in another. Other than the question of waiting only 20 seconds, there was full compliance with section 1531. It is our conclusion that under the circumstances of this case, silence for 20 seconds reasonably allowed the officer to conclude that his demand for admittance was being declined. This is particularly true in light of the fact the officer knew at that time that a crime was being perpetrated inside the residence." ( People v. Elder, supra, 63 Cal.App.3d at p. 739.)