The forensics so far released permits some comments about the device, followed with attempted profile of the perpetrator(s).
The damage is much less than expected, inconsistent with the size and effect of a typical vehicle IED. The lack of total wall collapse of adjacent buildings is indicative of a much smaller device than a camper could carry. It was either intentionally under-powered, or a fizzle. Since there is no mention of nails or ball bearings as lethality enhancers, lethality was not maximized. This fits well with an intentionally small device.
Since ANFO, ammonium nitrate/fuel oil, is the almost universal choice for car bombs, as well as the leading industrial explosive, a bomber’s illegal contacts would have to be very unusual to choose something else.
The color of the smoke is usually a clue to the type of explosive. In this case, the black smoke is likely an indication of a bomb maker’s error, or intentional sloppiness. Gross simplification: Almost all explosives, with the notable exception of TATP, contain all four of nitrogen, oxygen, carbon, and hydrogen.
- Nitrogen oxides tend to make orange smoke.
- Water, from hydrogen and oxygen, white smoke.
- Carbon, black smoke.
Which color you see depends upon which of the above is dominant. An optimal ANFO bomb produces orange smoke.
- An excess of fuel oil, more than the optimal 6%, results in black smoke from the carbon in the oil.
- An attempt to “boost” the IED by surrounding it with fuel oil in some dispersal scheme, perhaps for a fuel-air effect, could result in black smoke.
- If the bomb maker was environmentally minded, he might have mixed in PPC (Pittsburgh Pulverized Coal), to suppress toxic nitrogen oxides, with black smoke resulting.
An AT&T switching center is adjacent to the blast site. The choice of targets have been suggested as police, infrastructure, or a combination, where police would be drawn to respond by risk to infrastructure.
Goals of maximum loss of life or widespread emotional impact are not supported. The 15 minute countdown recording suggests a conscience more conditional than we have come to associate with Islamic terror. Since impact was actually minimized by the recorded warning, it is unlikely to have links to Islamic terrorism.
- The absence of a social media footprint suggests higher intelligence than typical of recent right-wing extremism.
- The possible human remains are consistent with a suicide attack.
- There has been no claim of responsibility. A lone wolf is possible.
If the perpetrator has ideological motivation, it may derive from
- Anarchism of the late 19th and early 20th century.
- Anti-fascism, as typified by the Weather Underground of 1969-1977, and the first and second wave Red Brigades of 1970-1988.
- The nascent potential for similar terror in the current Antifa movement.
Neo-naziism and Antifa are not simply polar opposites. The extreme right wing in the U.S., and probably elsewhere, is intellectually challenged. The further right we go, the dumber they get, eventually aligning with significant mental impairment. This broad grouping is almost incapable of ideating anything more sophisticated than the use of violence to incite more of the same. Notorious acts, such as the Oklahoma City bombing, have caused unselective loss of life.
We don’t have to love left-wing or anarchic radicals more than the right to acknowledge that the radical left, and the classical anarchists, think because they can. The intelligence of the modern Antifa grouping encourages elaborate ideations, typically actions of surgical scope. The Nashville bombing has, by design, noticeably limited scope.
The likely political sympathy is left. Whether it converts to political group association depends upon investigation. At best, this is a lone-wolf suicide. At worst, another Unabomber, difficult because of the intelligence of the perpetrator.
If Antifa is involved, publicity is key to the goal, and key also to the investigation.