I had the gall and stole my uncle's notebook from his room and what I found inside was shocking.
No kidding that was risky. What was inside the notebook?
I found some content about me, he was writing down his plots to kill me.
Normally it's wrong to steal from others, and you shouldn't have been doing so, but in this specific case, you might have unearthed some troubling ideas.  If you are not feeling safe, you should report your uncle to the authorities.
I never thought he would go this far. I have to finish him before he finish me.
I believe it's best to just take this evidence to the authorities, you wouldn't want to take matters into your own hands and have something go wrong. Despite you stealing, if you had a hunch, then it's okay. Just don't do it normally.