Homeland star cast as alien threat leader in Supergirl series

Homeland star David Harewood and Grey'S Anatomy regular Chyler Leigh have been added to the cast of the upcoming Supergirl TV series.

Harewood will play Hank Henshaw, a former CIA agent who heads up an alien threat team, while Leigh will portray the title character's foster sister, Alex Danvers.

The new additions join a cast that includes Glee star Melissa Benoist as Supergirl, Calista Flockhart, Laura Benanti and Mehcad Brooks.