That's because it is essentially spam. But don't feel bad. You are not the first person to be taken in by this.
A "citizen's grand jury" is just a figment of someone's imagination. It has no validity, no power, no anything. It exists just to fool others.
A couple buddies and I could just as easily form a "citizen's United Nations", and then announce that we have redrawn the national boundaries in Europe.
Thank you. That really needed to be done.