I'm trying to figure out a movie about a rich young girl(16-17yrs) that has a romance with one of her house workers, she has sex with him in her fathers library which her sister sees them. The sister is about 10-12 and she also likes the guy. She tells her parents, and he leaves and goes to war. I THINK they write to each other, later the guy comes back and takes the older sister with him. The younger sister becomes a nurse and helps cure the injure that have fought in war...

Atonement (http://www.imdb.com/title/tt0783233/)

I'm taring to find a movie that a murder kill the reporters by using a Laser gun from his house. If I'm not wrong, he has planned to kill their president by using this gun.The weapon has made by himself and polices couldn't tracing him. Unfortunately I can remember just these parts of the movie.
I really appreciate of somebody who is going to help me.

Atonement (http://www.imdb.com/title/tt0783233/)

agree it is atonement With kiera knightly and james mcAvory

Correct... atonement