Some mysteries can be solved by using investigative research, or deductive reasoning. There are some mysteries, however, that can never really be solved, such as paradoxes--if you go back in time and...
In the movie, yes. Susie Salmon's sister Lindsy, sneaks into Mr. Harveys house and finds a book of pics of susie, pieces of susies hair, ete. ete.I'm not so sure about the book though.