CNN's May 27, 2021 video 'Frustrated and concerned': Haberman reveals Trump's view of NY probe includes a short interview with "New York Law School professor and former Manhattan assistant district attorney" Rebecca Roiphe who says after
And one other thing that I just wanted to point out is the New York grand jury is different from the federal grand jury in a couple of important (ways.) One way is that you can’t present hearsay evidence which means like the evidence you present is basically the same quality evidence you’d have to present at trial. That makes it harder. Also witnesses get immunity, so you really have to kind-of build your case before you go in and be pretty sure.
Question: Why and when did New York State decide to run grand jury investigations with these differences from the way the US federal grand juries investigate? Are these the main differences or are there more significant differences?