do you have to answer the door for cops?

about an hour ago my bf saw two people outside his house, he said he thinks the man was on top of the woman and she was screaming, it was dark out so he couldn’t see much. He called the police and by the time he was done on the phone the man and woman were gone. Not sure if it was a couple or if they didn’t know each other. He told the cops that he wanted to remain anonymous and didn’t want them to come to the door because he doesn’t want the people to know it was him. He lives in a bad neighborhood where there have been shootings and we also have a kid that lives with him part time so he just didn’t want to be involved and have someone find out that he was the one that called. If the cops end up coming to his door, does he have to answer?

edit: okay thank u, we’ve had cops come to the door for other things that have happened in the neighborhood so that’s why he was worried but they went to his neighbors house, who we’re assuming also called, and then left