The simulation that concluded government agents did not fire their guns during the Branch Davidian siege did not test the type of assault rifle the FBI had at the scene, according to an official who helped run the test.
The simulation last year used a standard M-16 military rifle with a 20-inch barrel, said Robert Stewart, a U.S. Postal Service inspector who helped coordinate the simulation.
The FBI does not use standard M-16s, and members of its Hostage Rescue Team who were at the compound near Waco, Texas, in 1993 carried a version with a 14-inch barrel, an FBI spokeswoman said.
Firearms experts say the longer gun has less muzzle flash.
Lawyers for the Branch Davidians who survived the fiery end of the siege in April 1993 are now questioning whether the test really proved that FBI agents never fired their guns at the Davidian compound.
"I think it completely undermines the test results," attorney Michael Caddell said. Caddell said he plans to use the test as evidence if the lawsuit his clients filed against the government is restored on appeal.
Former Sen. John C. Danforth, who led the independent siege review, said he did not know specifics about the test gun. He said it would not change his conclusion that the FBI did not fire upon the Davidians at the end of the siege. Eighty Davidians died.
"I don't know what weapons were tested myself," Danforth said Friday. "But all of this was part of the agreement, and all of it was pronounced fair at the end of the test."
Danforth said Friday that he thought he received "something less than total cooperation" from the FBI, although he said that did not change his findings absolving the FBI of blame for the Davidians' deaths.
"Do I think there's anything out there hidden in some drawer that would affect the outcome? I don't think there's any chance of that," Danforth said.
John Collingwood, the FBI spokesman, cited Danforth's final report on the siege, which said problems with the FBI's performance in turning over documentary evidence were eventually settled to Danforth's satisfaction.
Stewart said the military's M-16 rifle that testers used had a 20-inch barrel, not the 14-inch carbine that the FBI had at Waco. He provided documentary filmmaker Mike McNulty with a photograph of the gun tested.
"We tested a standard military issue M-16, not a carbine," Stewart said.
The Davidian lawyers sought the simulation on March 19, 2000, because they believed flashes of light that appeared on infrared video from the final moments of the siege could be muzzle flashes from FBI guns.
Experts from British contractor Vector Data Systems concluded the flashes on the April 19, 1993, tape were glints from the sun, not gunfire.
Danforth and U.S. District Judge Walter S. Smith Jr. relied in part on that information to conclude that FBI agents did not fire their guns at the Davidian compound.
Firearms experts say the difference in barrel lengths could have affected the test.