After studying for four months, I passed the written exam in the 27th exam session. As someone without a background in the field, I found this e-book useful for building a foundation of basic knowledge. After that, I somehow obtained the new written-exam textbook published by the Forensics Society, as well as an out-of-print written-exam textbook, and studied them to fill in the gaps. In the actual exam, more than 80% of the questions in Subjects 1 through 3 were based on past questions included in the book. Although I saw many new questions in Subjects 4 and 5, they seemed to be at a level that could be inferred to some extent if you had studied consistently.