The link for complaints: https://cjc.ny.gov/General.Information/Gen.Info.Pages/NYC.Mail.Complaint.html
Ah, should've linked it to the original post, thanks! We wrote a bit about how to complain about judges here and prosecutors here.
In NY state people can complain about judges to NYS Commission on Judicial Conduct (CJC), which you've linked.
And to complain about prosecutors one can either submit a complaint to NYS Commission on Prosecutorial Conduct (CPC) or file a grievance with Attorney Grievance Committee (AGC). The latter one used to be the main path to complain about prosecutors before CPC was established. Joel has been reported for prosecutorial misconduct before. But also you can complain about prosecutors' unethical or incompetent actions/behaviors, too.