It was a long and cumbersome project. Plus, they were short of manpower. Fortunately, there was Bell, the artificial intelligence--or artificially-intelligent life-form. She could archive and organize a large number of videos and then replay them to Xiao Lin and the others to watch one by one.
For example, she would first cut all the trivial Wang Dalin time out of the video, such as eating or sleeping in class and so on. The president still had absolute confidence in the courses and teachers that he arranged, and it was impossible for someone to learn forbidden techniques in class. It could only be done in private.
Soon, their investigation focus fell on the library again, because they found that in the last two months of the last semester, Wang Dalin spent a considerable amount of time in the library. For this reason, they brought up Wang Dalin's borrowing records.