Nothing. The original charges were trumped up by ATFags.
House of Representatives Report 104-749 8/2/96 Committee of Government Reform & Oversight "..."The staff also had an opportunity to inspect the physical evidence taken from the ruins of the residence after the fire, much of which had been used in the criminal trial of surviving Davidians. By prior agreement with the Justice Department, a potential witness at the hearings, Failure Analysis Associates, Inc., was to inspect some of the physical evidence in order to respond to tampering allegations. It was believed that the views of scientists from Failure Analysis, who had often performed scientific evaluations for the Federal Government, including the Justice Department and NASA after the Challenger explosion, would be beneficial given public suspicions about the firearms recovered from the site of the Davidian residence. The inspection would not have damaged the weapons and was to have been conducted in the presence of all parties. It was hoped that the inspection would determine whether the Davidians had attempted to alter legal, semi-automatic weapons by converting them into illegal, automatic weapons as the ATF had alleged, and whether any of this evidence had been altered after it was gathered from the destroyed Davidian residence. When the scientists arrived in Austin, the Department declined to make the firearms available to them. The Department agreed instead to conduct the tests itself and present its findings to the subcommittees. A short time later, the Department urged, for cost considerations, that the tests not be performed. As a result, no tests were performed on the firearms." ....."
Interesting fact.