I am familiar with the history of the Hebrew Bible (OT to Christians), having had an extensive Jewish education in my youth. The Dead Sea scrolls, the Septuagint, the Vulgate, the Syriac Peshitta, Targums, and the Juxta Hebraica of Jerome are all at least 1000 years later than Moses. The controversy is whether the Pentateuch was actually written by Moses himself, or written in the days of Kings David and Solomon and edited in the days of Ezra. Ezra was still 500 years or so before the earliest manuscripts existing, so even the earliest manuscripts can't answer the question.
For a good discussion of the controversy, written from a Jewish perspective, you could check out this book.
OK thanks for the link. Do you trust PBS’s take on this subject? Or for that matter any subject.