Sasha Alexander is an American actress. She played the role of Gretchen Witter on Dawson's Creek. She also acted in feature films such as Yes Man; and He's Just Not That Into You. Alexander also acted as former Secret Service/NCIS Special Agent Kate Todd for the first two seasons of NCIS. Since July 2010, she has starred as Maura Isles on the TNT series Rizzoli & Isles.