Lots of people think that Toby is the Scranton Strangler but I beg to differ. As we know in Season 9, the employees of Dunder Mifflin had no clue that the camera crew was recording them for the majority of The Office. That's why a lot of the stuff they did they had no clue anyone was watching. This means that, in the 9 years of the documentary, they wouldn't have caught Toby strangle somebody at least once? I think they would have if they were recording everyone all the time.
You also don't think he would have tried to strangle Michael or even Jim?