woman attempts to drown baby, kills family then commits suicide (open scene)

i remember watching this movie sometime between 2011-2012, open scene is in a tub thats being filled up with water while a woman kills entire family, after that she puts the baby in the tub and kills herself.

-middle part of movie i just remember this couple (satanic cult?) having sex covering their heads with a wooden box and an upside down cross on it

Got something to say?