A lawyer for the Branch Davidians challenged the federal government Wednesday to join in scientific infrared field tests that he says will prove his experts' contention that agents fired guns at the group's compound on the last day of a 1993 standoff near Waco.
"The results of this demonstration will prove conclusively that the only possible explanation for the flashes seen on FBI FLIR [infrared video] tapes from April 19, 1993, is gunfire," Michael Caddell of Houston wrote in a four-page letter to the Department of Justice. "The refusal of the FBI to participate will certainly be interpreted as an admission of liability."
FBI and Justice Department officials didn't have much to say about the matter Wednesday night.
"We're reviewing the letter," said Justice Department official Myron Marlin, declining further comment.
A Maryland scientist retained by the Justice Department to help defend the government in the pending Branch Davidian case said his company has found no recorded evidence of gunfire.
"According to our analysis, it isn't gunfire," said Norris Krone, an aeronautical engineer whose Maryland Advanced Development Laboratory has used computer programs developed for a sniper-detection project to study the FBI infrared tapes. "It doesn't have a signature that resembles gunfire"
He declined to detail his lab's analysis, noting only that it determined that the FBI camera was too far away to record muzzle flashes from weapons on the ground and that white blips on the infrared videotape last too long to be from gunfire. He declined to say what might have caused the flashes.
"I could speculate, but I wouldn't want to. It just leads to more controversy," he said.

Disputed cause

Officials with the FBI and the Justice Department long have vehemently denied that any FBI agent fired a single shot at the Davidian compound during the 51-day standoff. They have dismissed the allegations in the Davidians' wrongful death lawsuit as baseless, arguing that Davidians alone were responsible for the standoff's tragic end.
Leader David Koresh and more than 80 followers died in a fire that erupted April 19, 1993, about six hours after FBI tanks began bashing the compound and spraying in tear gas. An FBI airplane circling the compound used an infrared video camera to capture the outbreak of the fire and the hours that preceded it.
Infrared cameras record images in black and white by measuring and capturing temperature differences. For the crucial hours just before the compound burned, the FBI's infrared camera was set to make hotter objects appear lighter and cooler objects appear darker as it scanned the landscape below.
Just after 12:08 p.m., the airborne camera recorded the white flashes of three fires breaking out in the compound within a three-minute period. Arson experts used that footage to conclude that sect members deliberately set the fires.
In the hour that preceded the fire, the infrared camera also captured repeated bursts of white flashes erupting from both government positions and from the windows of the Davidian compound. On recently released, high-quality copies of the FBI infrared recordings, some bursts of white flashes come out of Davidian windows toward maneuvering FBI tanks.
Others appear near FBI tanks and move in the direction of the compound.

Flashes detailed

In a time line sent to Justice Department lawyers along with his challenge Wednesday, Mr. Caddell indicated that his law firm has identified 32 separate "flash" events.
Nine of those flash events appeared to come from government positions and 15 from the Davidians, he wrote. He contended that eight were of unclear origin but were probably caused largely by home-made Davidian hand grenades or the launching of government "flash-bang" distraction devices - ordnance that government officials have denied using on April 19.
The devices explode with a loud bang and a blinding flash and are commonly used to distract suspects. FBI agents fired them at least seven times in the last two weeks of the siege, using them to scare Davidians back into the compound when they came outside without government permission.
FBI officials have insisted that its agents used no flash-bang devices during their final tank-and-tear-gas assault. But FBI records indicate that one of the earliest proposals pitched by its tactical experts included a plan to lob the distraction devices repeatedly into the building as FBI tanks pumped tear gas inside.
The plan, dated March 11, proposed launching an assault on March 11 or on March 12, the day that Attorney General Janet Reno was sworn into office.
Mr. Caddell has said that he believes that government agents involved in the April 19 assault began firing guns at the Davidians to defend the government's tanks.

Citing experts

He noted in his Wednesday letter that his assessment has been supported by scientific experts hired by outside media and the House Government Reform Committee, which recently began a new investigation of the Davidian incident.
An expert for the House committee said last month that his preliminary evaluation of the infrared tape indicated that it did capture the thermal images of government gunfire. He was allowed on Friday to study the FBI's original copy of the tape for the first time and is still working on his final analysis, said committee spokesman Mark Carollo.
"He stands by his initial assessment," Mr. Carollo said. "However, he has not submitted any formal findings, and we're still very early in the game."
Mr. Caddell told the Justice Department on Wednesday that he will invite the House committee's expert and other outsiders, including representatives from the office of independent counsel John Danforth, to participate in a full field test of infrared cameras.
He said he would also invite Dr. Krone's lab to participate, noting that his laboratory, retained as government experts, has offered "no credible explanation for the numerous flashes . . . flashes which have the abrupt, precise and repetitive signature of gunfire. . . ."
The test would be staged at a Dallas-area gun club using an airborne camera similar to the one used by the FBI in Waco. It would record gunshots on the ground from firearms similar to those deployed by both government agents and the Davidians.
Mr. Carollo said the committee "would welcome" such a test, adding that a "side-by-side analysis," of the FBI's recording and a test recording might help resolve the gunfire issue.
If the field test did produce results matching what was recorded on FBI cameras, Mr. Caddell said, he would ask a federal judge overseeing the ongoing wrongful death case to impose "appropriate sanctions against the persons responsible for perpetrating this massive lie. . . ."
Government officials could avoid that by agreeing to admit that its agents did fire at the compound on April 19, he wrote. "We can then deal with the real issues in this case: who was shooting from government position, and when did that gunfire impede or prevent the escape of women and children from the burning building?"

WASHINGTON (AP) - In a high-stakes challenge to the government, lawyers for survivors of the 1993 Waco siege are offering to put to the test their claim that federal agents fired into the Branch Davidian compound during the deadly standoff's final hours.
The lead lawyer in a wrongful-death lawsuit filed against the government proposed Wednesday to stage a demonstration - attended by experts for the FBI, Congress and the special counsel investigating Waco - recreating conditions similar to those present when the FBI recorded aerial infrared footage of the siege's final hours.
``The results of this demonstration will prove conclusively that the only possible explanation for the flashes seen on the FBI (infrared) tapes from April 19, 1993 is government gunfire,'' Houston lawyer Michael Caddell wrote the Justice Department.
The FBI cautioned that it would be ``near impossible'' to duplicate conditions - particularly since the plaintiffs lack crucial information about the altitude of the FBI plane that flew over the Texas compound, the infrared camera's design specifications and film speed.
Furor over Waco was touched off anew in late August, with the FBI's belated admission that potentially incendiary tear gas canisters were fired hours before the Davidians' retreat erupted in flames.
Congressional inquiries are underway and Attorney General Janet Reno appointed a special counsel who has said he will examine Waco's ``dark questions'' - including whether federal agents fired shots on the final day.
The government long has insisted FBI agents did not fire any shots during the 51-day siege. Some 80 Davidians died April 19, some from the fire, others from gunshot wounds. Federal officials concluded the gunshot victims killed themselves or died at the hands of sect members intent on fulfilling a prophecy of mass suicide.
But Caddell and his allies, who are prepared to go to trial next spring, contend the infrared surveillance footage offers ``irrefutable'' proof that federal forces fired into the building during the standoff's waning hours.
The Justice Department provided little reaction to the offer. ``We'll have to review the letter,'' said department spokesman Myron Marlin, declining further comment.
But an FBI official, speaking on condition of anonymity, said it would be ``near impossible'' to recreate the exact conditions present that day.
Caddell has been stymied in his campaign to learn more about the infrared camera. The Justice Department refused to provide the information, saying the camera's specifications are classified.
In his letter, Caddell said he merely requires confirmation that an infrared camera in the plaintiffs' possession is similar to the one the FBI used. With such confirmation, he proposed to use a plane similar to the FBI's ``Nightstalker'' aircraft to fly over a Dallas area firing range, recording infrared images of gunfire from weapons similar to those carried by Davidians and federal agents.
The FBI source said details of the infrared equipment, used in sensitive law enforcement cases, must be shielded to keep the technology viable. ``The assumption would be (the plaintiffs' lawyers) are trying to use the media to force what they could not get'' through discovery, the official said.
While the FBI questioned the proposed demonstration's worth, a spokesman for a congressional panel that is investigating Waco suggested a test could have merit.
The House Government Reform Committee would ``welcome a scientific test that would enable us to do a side-by-side analysis with the FBI (infrared) tape,'' spokesman Mark Corallo said.
An infrared expert retained by the committee, as well as others consulted by the plaintiffs and several media organizations, have concluded that bursts of light on the FBI's tapes represent gunfire from government positions, Caddell noted.
``The only `experts' who dispute these conclusions are on the government's payroll,'' he added, deriding government theories that the light flashes represent sunlight glinting off water puddles, metal shards or debris.
But the president of a Maryland laboratory to whom FBI officials have steered reporters reiterated his lab's view - held since its experts first examined the tapes in 1997 at a newspaper's request - that the flashes don't represent gunfire.
``What's purported to be gunfire, we don't believe is gunfire,'' said Norris J. Krone Jr., president of the Maryland Advanced Development Laboratory. He declined to discuss whether FBI or Justice have contracted with his lab regarding Waco.