The video on the Dead Sea Scrolls provides an overview of how the scrolls were discovered and what scholars have learned. One topic that has been argued over the years is who wrote the scrolls. Initially it was supposed that they were written by the Essenes, a Jewish separatist sect. Others, like Norman Golb, have suggested that there is no evidence for the Essene hypothesis.
Loren Stuckenbruck, my Doctor Father from Durham, provides some reasons for why the Essene hypothesis is the best guess for who wrote the scrolls.