It's The DA's Call?

I've been an attorney for 15 years, I know of no jurisdiction in the country where it's the DA's call on whether to make an arrest. When the police are interviewing Berkley she asks them if they are going to arrest the kid and one of the detectives responds, "I don't know, it's the DA's call." The DA may decide not to prosecute a case but no cop would first check with a DA when deciding to make an arrest. Just sloppy writing.