Can a prosecutor ask improper questions about a witness?

Moreover, to the extent defendants believed the prosecutor's questions regarding those topics were improper, they could have objected, but for the most part they did not. Thus, they have forfeited any complaint on appeal regarding the propriety of those questions. In sum, the record establishes that the prosecutor called a witness he believed would be helpful to his case, and that the prosecutor's questions were asked in a good faith belief that the witness had knowledge of those topics. (Cf. People v. Pearson (2013) 56 Cal.4th 393, 434 ["A prosecutor may not ask questions of a witness suggesting facts harmful to a defendant without a good faith belief that such facts exist."].)