why do journalists and authors often put brackets around words in seemingly strange parts of sentences?

Question

For example, a sentence I just read went as follows:

> “‘I don’t think [the book] had anything to do with his arrest and neither does Anne Marie Schubert,’ he says.”—(Excerpt from the appendix of ‘I’ll Be Gone in the Dark’ by Michelle McNamara)

Found in Other.

Answer 1

Those are to fill in words the person didn’t say.

>I don’t think [the book] had anything to do with his arrest and neither does Anne Marie Schubert

Probably was

>I don’t think *it* had anything to do with his arrest and neither does Anne Marie Schubert

So they made sure it was clear what subject they were discussing so the reader would understand.

The brackets indicate a redaction by the journalist or editor.