In May 1992, Chief Deputy Daniel Weyenberg of the McLennan County Sheriff's Department called the ATF notifying that his office had been contacted by the local United Parcel Service regarding a driver seeing a package that had broken open on delivery to the Branch Davidian residence, revealing that it contained firearms, inert grenade casings, and black powder. On June 9, 1992 a formal investigation was opened and a week later it was classified as sensitive, thereby calling for a high degree of oversight from both Houston and Headquarters (italics on the original).[13][14]
The documentary Inside Waco claims that the investigation started when in 1992 the ATF became concerned over reports of automatic gunfire coming from the Carmel compound.[15]
The ATF began surveillance from a house across the road from the compound, but their cover was noticeably poor (the "college students" were in their 30s, not registered at the local schools, and they did not keep a schedule which would have fit any legitimate employment or classes).[16] Subsequent investigations, including sending in one agent undercover, revealed that there were over 150 weapons and 8,000 rounds of ammunition in the compound. Most of the weapons were legal semi-automatics; however, the ATF alleged there were also a number of fire-arms that had been illegally modified to fire full-automatic.[15]
Davy Aguilera, the ATF agent that had prepared the affidavit, testified later on the trial that a neighbor heard machine-gun fire; but Aguilera failed to tell the magistrate that the same neighbor had previously reported the noise to the sheriff, who investigated the noise. The sheriff found Koresh had a *lawful* item called a hellfire device, which allows a semi-automatic firearm to fire at a rate approaching that of fully automatic firearms. The affidavit was approved by a U.S. magistrate and was used as a base for warrants.[17]
Alleging that the Davidians had violated federal law, the ATF obtained search and arrest warrants for Koresh and specific followers on weapons charges due to the many firearms they had accumulated, and they planned their raid for March 1, 1993, with the code name "Showtime".[18] However, the raid was moved up a day in response to the Waco Tribune-Herald "Sinful Messiah" article (which the ATF had tried to prevent from being published).[15]
