Help with a personal project

Hi friends, I'm thinking about writing a story that's been in my head for a while.

But the thing is, I don't want to do it in the typical novel format; rather, I want to do it as a confidential police investigation file or record. At first, I thought about writing it as a diary, but when I started writing it, it was pretty boring to read.

Do you have any ideas or opinions that would help me accomplish this?