Balance
I would strongly suggest watching the PBS Frontline documentary in addition to this. It has things in it that are not in this documentary, though it is 1/2 the length.
http://vimeo.com/13978271 (not sure how long this link will work.)
http://www.pbs.org/wgbh/pages/frontline/waco/
This documentary is professionally produced. But mostly gives interviews and perspectives from the Davidians side. The clips shown from the government officials are from news conferences and congressional hearings, but not separate interviews like are shown for the Davidians. And at the government hearings, it is mostly Republicans asking questions. The times Democrats are shown, what they said is often contradicted or belittled immediately by someone associated with the Davidians.
It shows the ATF and FBI in a very bad light, sometimes justifiably. But for balance watch the PBS documentary also.
Why it ever came to a showdown like this is not explored. It never should have gotten to a military confrontation.