D.C. Code § 21-904: Admission upon written application; right of release.

A person in a place specified by section 21-902 may, upon his written application, be admitted for observation and diagnosis to Saint Elizabeths Hospital in the discretion of the Superintendent of the hospital for a period not exceeding 30 days. If, after admission to Saint Elizabeths Hospital, he expresses a desire for release from the hospital, he shall be released within 72 hours thereafter, unless proceedings for his adjudication as a person with a mental illness have been instituted as provided for by section 21-906 .