How does the author use symbolism in the novel, The Trespasser?

Throughout the novel, the author uses windows to illustrate the way in which people can watch - but not truly see - what is going on and what the truth is. Rory watches Aislinn, and by doing this he put her on a pedestal. If he had not done that, he might have been more skeptical about why she had not answered her phone.

Conway also sees someone lurking outside her apartment through her window. In this case, too, she thinks it is a stalker or someone who is involved with the case. It is not, and it is, in fact, someone who has distorted her truth since she was a child - her father.