Is the ending of the movie "Taking Lives" legally justified?

At the end of Taking Lives

we see that it was James Costa aka Martin Asher who is the real killer. But by that time this is discovered he has had sex with Scott, has taken another life and has escaped. Scott is terminated from her service at the FBI for her conduct. In the last scene, few months later, we see Scott, pregnant, coming from a store to a secluded house living all alone. Asher/Costa arrives there and abuses and threatens her to start fresh with him. Finally he loses his mind and stabs Scott in her belly, but Scott pulls back the scissors and stabs his chest revealing that this whole thing was staged(she isn't pregnant) to nab Costa/Asher. Scott then tells Leclair about their success.

My question is if this whole sacking of Scott and her living secluded, pregnant, was a set up to catch Asher/Costa, as he would come to her, How can Scott kill him? She is bound by the law, this whole thing was a setup by the authorities. She expected Asher/Costa to abuse her when he came and possibly attempt to kill her, but how can she kill him and get away with the law. He is not a convicted murderer. He hasn't undergone a trial.

Also, Leclair must have known that Asher/Costa would try to harm her, so why didn't he have an arrangement to catch the killer alive. Is this setup and most importantly, the killing part, legally justified?

Best Answer

In the United States you can respond with lethal force if someone attempts to kill you, in an effort to protect yourself from further harm. The film makes it abundantly clear that this is Asher's intent when he stabs Scott in the stomach with the pair of shears and also tries to strangle her.

While the film ends with the rather dubious showing of Scott (Angelina Jolie) calling someone (apparently the police) and speaking the line (unnecessarily) "It's over" there really is no need for her to do so. Someone breaking into your home and then attacking you is more than satisfactory legal cause for you to defend yourself up to, and including, lethal force.

Also, Pennsylvania (the setting for the end of the film) now has, and always had, strong laws enabling the potential victim of a crime to defend themselves along the lines of Florida's controversial "Stand Your Ground" legal protection. This means that the victim does not have to retreat if/when they are attacked and that they can use lethal force at any time during an assault.

The only "problematic" portion of the film seems to have been the use of prosthetic abdomen to make it appear that Scott was pregnant. However, Asher's breaking into her home and then assaulting her with a potentially deadly weapon even removes that particular obstacle as she was legally able to "stand her ground" when she was attacked.

References:

http://publicsource.org/investigations/pas-stand-your-ground-law-mirrors-floridashttp://www.ncsl.org/research/civil-and-criminal-justice/self-defense-and-stand-your-ground.aspx