Season 4 of The Killing was released on Netflix on August 1st, 2014.
The cast for season 4 included series stars Mireille Enos (Sarah Linden) and Joel Kinnaman (Stephen Holder) and Gregg Henry (Carl Reddick), and some new cast members, such as Tyler Ross, Sterling Beaumon, Levi Meaden and Joan Allen.
Season 4 is available on Netflix in all territories.
The Killing Fans Blog 
Hope season 4 soon comes out
WORD! I need season 4 :)
Love love love this show, best show I´ve ever seen:)