D.C. Code § 22-3808
Upon the evidence introduced at a hearing held for that purpose, the court shall determine whether or not the patient is a sexual psychopath. Such hearing shall be conducted without a jury unless, before such hearing and within 15 days after the date on which the second report is filed pursuant to § 22-3806, a jury is demanded by the patient or by the officer filing the statement. The rules of evidence applicable in judicial proceedings in the court shall be applicable to hearings pursuant to this section; but, notwithstanding any such rule, evidence of conviction of any number of crimes the commission of which tends to show that the patient is a sexual psychopath and of the punishment inflicted therefor shall be admissible at any such hearing. The patient shall be entitled to an appeal as in other cases. If the patient is determined to be a sexual psychopath, the court shall commit him or her to an institution to be confined there until released in accordance with § 22-3809.
D.C. Code § 22-3808