Caitlin Maguire (Aubrey Peeples) was not kidnapped and murdered by the Russian mafia. She was accidentally shot and killed by her friend Mike (Max Fowler). Caitlin had been pressured into showing some of her father's guns by Mike and Evan. When they were playing around with them, Caitlin startled Mike and he accidentally pulled the trigger. Mike and Evan then dumped her body and made up the home invasion story.
Paul Maguire (Nicolas Cage) realizes too late that the gun he stole from a robbery 15 years before was the gun that killed his daughter. He had already started a mob war with Chernov (Pasha D. Lychnikoff) the man who he believed killed his daughter. This revenge rampage has caused the deaths of Kane (Max Ryan), Danny (Michael McGrady) and O'Connell (Peter Stormare).
Paul goes home and sees that Russian gangsters are about to enter to kill him in retaliation. He quickly calls his wife Vanessa (Rachel Nichols) and apologizes for failing her. The gunmen enter the room Paul is in and kill him.