Activists have called for cases handled by Linda Fairstein and Elizabeth Lederer to be reviewed following the release of Netflix series "When They See Us."
He had faced scrutiny in October for having dropped cases after receiving campaign contributions from lawyers.
The district attorney received political donations from lawyers connected to cases he dropped.
Ivanka Trump and Donald Trump Jr. were entrenched in an investigation after they reportedly discussed via email ways they could lie to prospective buyers about condos.
The hearing signals the first move by Congress, which has stayed quiet so far on the iPhone encryption case.