The show you are likely thinking of is "The Alienist", which premiered in 2018, not 2012.
Here are some of the main actors and actresses who appeared in "The Alienist":
* Daniel Brühl as Dr. Laszlo Kreizler
* Luke Evans as John Moore
* Dakota Fanning as Sara Howard
* Brian Geraghty as Marcus Isaacson
* Matthew Shear as Stevie
* Robert Wisdom as Cyrus
* Douglas Smith as Billy the Butcher
* Q'orianka Kilcher as Mary
* Michael Aronov as D.S. Theodore Roosevelt
If you're looking for information about another movie or TV show with a similar name, please provide more details.