An objection to an individual grand juror may be based on the cause that the grand juror:
(1) is less than 18 years of age;
(2) is not a citizen of the United States;
(3) has not resided in this state 30 days;
(4) lacks mental capacity;
(5) is a prosecutor upon a charge against the defendant;
(6) is a witness on the part of the prosecution, and has been served with process or bound by recognizance as such; or
(7) is of a state of mind in reference to the case or to either party which shall satisfy the court, in the exercise of a sound discretion, that the juror cannot act impartially and without prejudice to the substantial rights of the party objecting.