Stephen D. Vermillion, 52, the chief of staff to U.S. Rep. David Rivera (R-Fla.), died Nov. 15 at his home in Washington.

He had leukemia, his sister-in-law Karen Iker said.

Mr. Vermillion worked on Capitol Hill for 17 years. His previous positions included chief of staff to then-Rep. Lincoln Diaz-Balart (R-Fla.), communications director to then-Rep. Bob Livingston (R-La.) and military and national security adviser to Rep. F. James Sensenbrenner Jr. (R-Wis.).

Mr. Vermillion had also been vice president of government affairs with ObjectVideo, a security software company, and director of congressional relations at the Cuban American National Foundation.

Stephen Dorsey Vermillion III was born in Washington and spent part of his childhood in Latin America, where his father was stationed by the CIA.

Mr. Vermillion was a 1978 graduate of St. John’s College High School in Washington. He received a bachelor’s degree in political science and Spanish from Loyola University Maryland in 1982 and later a master’s degree in international studies from the University of Miami in Coral Gables, Fla.He did postgraduate work in national security studies at the U.S. Naval War College.

He was a competitive rower and had held leadership positions with the Potomac Boat Club and the Capital Rowing Club. Mr. Vermillion won national and international competitions with the clubs.

Survivors include his wife of 18 years, Jennifer Iker Vermillion, and two children, Sarah Vermillion and Joseph Vermillion, all of Washington; his mother, Alice Cleary Vermillion of Charlotte; two brothers; and a sister.

— Emily Langer