Challenges by state, when, and causes

1. The state may challenge the panel of a grand jury or an individual grand juror at any time before the grand jury is impaneled and sworn. 2. A challenge to the panel may be asserted by the state upon the ground only that the grand jurors were not selected according to law. 3. A challenge to an individual grand juror may be asserted by the state upon the ground only that the person is not a qualified juror.