So, I'm wondering while watching this film, did the producers of this movie get to save money on Sandra Bullock's wardrobe by dragging out her "before" clothes from Miss Congeniality? Did Ms. Bullock also get to sleepwalk through the role by channeling the "before" Gracie Hart? As many reviewers have noted before, the film is very formulaic. Add to that the deja vu viewer experiences with the character of Cassie Maywether as a somewhat darker Gracie Hart with more back story and it rapidly become a snooze fest.
The two bad boy serial killers have been done before (and better) in other films. As has the "good guy partner trying to protect his partner despite the evidence" character been seen before. In fact none of the characters in the film ever get beyond two dimensions or try to be anything but trite stereotypes.
One last peeve - using the term serial killer is false advertising. Murdering one person - even if it's a premeditated murder - does not make you a serial killer. You may have the potential to become a serial killer but you are not a serial killer or even a spree killer.