They've sworn to it in court, and they've testified to it for Congress: "During that time, those six hours, and indeed those 51 days, the FBI never fired one shot at the Davidians," said FBI official Dick Rogers.
It is a crucial pillar of truth for the FBI, and about to become even more so. Former Sen. John Danforth has made it a focus of his new investigation of the siege. And it's the key question in a lawsuit against the FBI.
Surviving Davidians have sued the Bureau for $100 million, alleging the FBI kept them pinned inside the burning compound with gunfire. The issue goes to trial early next year, and in recent days, both sides have given glimpses of their evidence to the press.
Dr. Ed Allard has maintained for five years that tiny flashes seen on an FBI infrared aerial surveillance tape are actually gunfire.
Allard said there is no doubt in his mind that the FBI fired weapons at Waco and that he counted 65 rounds that were fired.
Allard will testify for the Davidians, but will admit that he himself has never attempted to detect gunfire with an airborne infrared device. Dr. Norris Krone, on the other hand, has, and he is likely to testify for the FBI.
"We do not think that was sniper fire based on our considered judgment and knowledge of those weapons," Krone said. The infrared expert declined to discuss what might have caused the tiny flashes seen on the tape.
The Bureau will also point to the sworn statements of every FBI agent present at Waco that day, and the answer to the question that each was asked concerning weapons: "No, I didn't fire," and "No, I saw no one else fire."
Only one agent has ever answered differently. FBI sniper Charles Riley said in a 1993 statement that he "heard shots fired" from another FBI sniper post. In 1996 he retracted that as "inaccurate."
It is hard to overstate how crucial this issue is for the FBI's credibility. It was only last month that the Bureau shocked the Justice Department and Congress with the discovery of new videotape of the Davidian siege.
If someone, or something, were to emerge now that suggests they did fire on the Davidians that long ago day, then the Bureau may find itself under siege.
©1999 CBS Worldwide Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed