Mark Danzinger began to work for S.H.I.E.L.D. at one point, stationed at San Conception. He eventually became a sergeant for S.H.IE.L.D.
Danzinger was created by renowned writer Frank Miller and artist Bill Sienkiewicz, first appearing in Elektra: Assassin #3.
Major Story Arcs
Danzinger finds Elektra breaking into the San Conception base whilst he's on a night-watch. Elektra notices him before she propels him into a glass door, rendering him unconscious.