According to
the Hollywood Reporter:
Marcos Siega has come aboard "Vampire Diaries." "Diaries," from WBTV and Alloy, is based on the series of novels and centers on a tragic young heroine who is the object of passion for two vampire brothers, one good and one evil. Siega's directing credits include "Dexter" and "Cold Case."
Marcos Siega on IMDb. Other credits include True Blood, Shark, Life, and Veronica Mars.