10 U.S.C. 47 - UNIFORM CODE OF MILITARY JUSTICE
https://www.gpo.gov/fdsys/granule/USCODE-2010-title10/USCODE-2010-title10-subtitleA-partII-chap47/content-detail.html
§ 906a. Art. 106a. Espionage
(c) A sentence of death may be adjudged by a court-martial for an offense under this section (article) only if the members unanimously find, beyond a reasonable doubt, one or more of the
following aggravating factors:
(1) The accused has been convicted of another offense involving espionage or treason for which either a sentence of death or imprisonment for life was authorized by statute.
(2) In the commission of the offense, the accused knowingly created a grave risk of substantial damage to the national security.
(3) In the commission of the offense, the accused knowingly created a grave risk of death to another person.
(4) Any other factor that may be prescribed by the President by regulations under section 836 of this title (article 36).
(Added Pub. L. 99–145, title V, §534(a), Nov. 8,
1985, 99 Stat. 634.)