§ 660.20 Examination of witnesses conditionally; grounds for order. An order directing examination of a witness conditionally must be based upon the ground that there is reasonable cause to believe that such witness: 1. Possesses information material to the criminal action or proceeding in issue; and 2. Will not be amenable or responsive to legal process or available as a witness at a time when his testimony will be sought, either because he is: (a) About to leave the state and not return for a substantial period of time; or (b) Physically ill or incapacited.