S.C. Code Ann. § 25-1-2755

At any time after charges have been signed, as provided in SECTION 25-1-2660, any party may take oral or written depositions unless the military judge or court-martial without a military judge hearing the case, or if the case is not being heard, an authority competent to convene a court-martial for the trial of those charges, forbids it for a good cause. If a deposition is to be taken before charges are referred for trial, an authority may designate commissioned officers to represent the prosecution and the defense and may authorize those officers to take the deposition of any witness. The party at whose instance a deposition is to be taken shall give to every other party reasonable written notice of the time and place for taking the deposition. Depositions may be taken before, and authenticated by, any military or civil officer authorized by the laws of this State or by the laws of the place where the deposition is taken to administer oaths. A duly authenticated deposition taken upon reasonable notice to the other parties, so far as otherwise admissible under the rules of evidence, may be read in evidence before any court-martial or in any proceeding before a court of inquiry, if it appears that: (1) the witness resides or is beyond the State or beyond the distance of one hundred miles from the place of trial or hearing; (2) the witness by reason of death, age, sickness, bodily infirmity, imprisonment, military necessity, nonamenability to process or other reasonable cause, is unable or refuses to appear to testify in person at the place of trial or hearing; (3) the present whereabouts of the witness is unknown.