Denver lawyer Daniel Kagan, who had already indicated his interest in running for the HD-3 seat in 2010, will replace Rep. Anne McGihon as the state representative for that district.
A Democratic party vacancy committee chose Kagan to fill the remainder of McGihon's term Thursday night.
Kagan, 56, emigrated to the United States from England when he was 22. He became an American citizen in 1984.
He holds an undergraduate degree in public affairs from George Washington University and a law degree from Yale University. He has practiced law at a large Washington, D.C. firm and in a partnership with his wife. Kagan was a member of the Teamsters Union in the 1970s.
Kagan, who was a delegate for then-U.S. Sen. Hillary Clinton's presidential campaign in 2008, is the father of three children.