The first chapter of Why Waco is available on-line: https://www.ucpress.edu/book.php?isbn=9780520208995 but the rest of the book gives the whole story. Highly recommend as a start.
In terms of the topic more generally there is the highly perceptive New Yorker piece by Malcom Gladwell. That was a major breakthrough and very important: https://www.newyorker.com/magazine/2014/03/31/sacred-and-profane-4.
C-Span also has my 1995 testimony before Congress with Dr. Philip Arnold. We are on throughout this link and at the end I am given an open mike to lay out the case as we see it: https://www.c-span.org/video/?66441-1/waco-investigation-day-5-part-3&start=6192&transcriptQuery=hearings
Here is a tape I made of “The Last Words of David Koresh,” which is quite important for understanding the last three days before the FBI assault with CS-Gas on April 19th. It is a large file but here is the Dropbox link: https://www.dropbox.com/s/4eg5bdpooeytnfg/LastWords%20Koresh.mp3?dl=0
Finally, if you have read all these you should work through this one: “Waco After 25 Years: Getting the Facts Straight.”