After the April 19, 1995, Oklahoma City bombing, conspiracy theories floated that the FBI and ATF lied about the number, type and location of the bombs.
The pattern of the bombing is among the evidence against the government's "single fertilizer bomb" theory. The damage was not centered around the truck bomb's location, and some munitions experts claim that no fertilizer bomb could have destroyed the building's support columns.
However, others have pointed out that geometric arrangement of ANFO barrels as well as other tamping methods could focus the energy of the explosion.
Glock hobbyist Nick Hull posted this excerpt from Tim Hudson's "Friends Faxing Friends" to the Usenet news group talk.politics.guns:
There were actually two explosions, the "truck bomb" blew first (for cover) outside the building and then a string of charges wired together that were physically placed on some of the building columns at ground level detonated seconds later. The second blast was set to cause maximum structural changes.
... The truckbomb could never have caused the pattern of damage that was evident from the newspaper photos. A truck bomb charge immense enough to break, from a distance, those reinforced concrete columns, would certainly blow out the exterior curtain wall at ground level on the opposite and undamaged side of the building. There is no such damage on the opposite side exterior wall, which is intact.
The pattern of blown columns is not close to being circular as would be expected if the blast emanated from one origin. As we know, the power of a detonation diminishes, proportionately as the distance (in all directions, i.e. circular) is increased. However, this pattern of destruction is essentially linear, except for one indentation that should have been, but is not directly opposite of the ground crater. ... Most incredibly, there are intact window frames closer to the center of the ground crater than are the missing concrete columns.
... The debris is blown out of the building as one would expect from an interior blast. An exterior blast would blow debris into the still standing interior of the building. In summary, this linear pattern is totally indicative of high brissance charges placed directly on columns. The 1200 lbs. of ammonium nitrate (a slow burn explosive) reported in the press could not have caused this kind of damage to support columns from that distance, no way.
Craig D.W. Hammond of Lawton, Oklahoma, reported to Libernet about local news coverage.
Hammond summarized an article in June 28, 1995, The Daily Oklahoman about an Oklahoma state legislator who disbelieves the government's version of the bombing.
Oklahoma State Rep. Charles Key, R-Oklahoma City, lost a close friend in the bombing. In a June 27 memorandum sent to his fellow legislators, Key called for an independent investigation, saying he does not believe a fertilizer bomb destroyed the federal building.
"I am convinced that the government is not being forthright about the kind of bomb(s), the number of explosions, the placement of the explosives and other crucial aspects of the April 19 bombing," Key said. "I'm convinced that for that building to come down like that, it had to have explosives at the columns to bring it down or at strategic places. The FBI is saying a truck bomb drove up and sat out front and blew up."
Key's memo included a copy of a letter from retired Air Force Brigadier General Benton K. Partin to U.S. Senator Don Nickles, R-Oklahoma. Partin's letter claims "the damage pattern on the reinforced concrete superstructure could not possibly have been attained from the single truck bomb without supplementing demolition charges at some of the reinforced column bases."
Hammond also summarized a June 28, 1995, television interview of Sam Cohen, inventor of the neutron bomb, by Oklahoma City NBC affiliate KFOR-TV. "I don't care how much fertilizer and fuel oil they used, it would never be enough," Cohen said. "Demolition charges placed at key column did the dirty work."