Find his test sites, top bomb experts say.
Anthony Quinn Warner’s device, although probably made of common over-the-counter components, is unique in the annals of mayhem, according to seasoned FBI bomb experts consulted by SpyTalk.
“We’ve never seen an improvised thermobaric device before in this country or any country,” says Dave Williams, who conducted the FBI’s on-scene investigations of the World Trade Center, Oklahoma City, Pan Am 103 and Unabomber bombings, among other notorious incidents. Thermobaric refers to a gaseous fuel-air explosion.
“The reason is, it’s very difficult to get the timing down to get an optimum mixture of air and a liquified carbonaceous fuel such as propane, methane, acetylene or natural gas,” Williams told SpyTalk. “He couldn’t have done it the first time and made it work. There had to be a test area.”
Accidental thermobaric explosions are not uncommon—for example, when a house explodes because of a natural gas leak. But IED-makers haven’t tried to stage them deliberately, up to now, Williams says, because too many things have to go right.
That’s why investigators must be eager to locate Warner’s proving ground, and also any internet sources he studied as he was building a timer and ignition mechanism that enabled him to blow up a Nashville city block, and himself, at 6:30 a.m. on Christmas Day.
As several news outlets have reported, on Aug. 21, 2019, Warner’s ex-girlfriend and her lawyer alerted Nashville police that Warner was “building bombs in the RV trailer” on his property and “frequently talks about the military and bomb-making.” The police referred the incident to the FBI, according to the reports, but neither agency obtained a search warrant to investigate the premises. The police report of the charges leveled by the ex-girlfriend and lawyer contains no hint of Warner’s evident mastery of bomb-making and related electronics.
Williams’ hypothesis, that Warner’s RV bomb was likely thermobaric, also known as a fuel-air explosive, aerosol bomb or vacuum bomb, is based on videos of the yellow-orange fireball, the pattern of destruction and conversations with other experts in the tight network of bomb investigators aware of the ongoing investigation in Nashville.