What was Crawford talking about??
This isn't a plot hole in the book but a major one in the movie. Crawford states there is absolutely no connection between the two families? The FBI transferred film of the Leeds and Jacobi families on video for Graham to view at the very beginning. How did the FBI not figure out both films were developed at Gateway Labs? The case should have been solved long before Crawford even went to Graham's house.
I believe in the book Graham has absolutely no idea the Jacobi's even had film until the end. He realizes after reading their probate papers from Metcalf that there's a projector and film missing from the storage room were the Jacobi's belongings are kept. He realizes after watching it that everything the killer needed to know about the killings were on the two films and realizes both films were from Gateway.