The 1995 Oklahoma City Bombing

By Michael Rivero

A brief overview of the official story of the Oklahoma City bombing:

On April 17, 1995 Timothy McVeigh reportedly picked up a 20-foot Ryder truck from Elliott's Body Shop in Junction City. The truck was filled with roughly 5,000 pounds (2,300 kg) of ammonium nitrate, an agricultural fertilizer, and nitromethane, a highly volatile motor-racing fuel-a mixture also known as Kinepak or ANFO (ammonium nitrate/fuel oil).

At 9:02 a.m. on April 19, 1995,  the truck exploded in the street in front of the Alfred P. Murrah federal building. About 90 minutes later, McVeigh was stopped by an Oklahoma state trooper for driving a vehicle without a license plate, who then arrested him on a firearms charge. Two days later he was charged in the bombing. His friend Terry Nichols was arrested in Kansas, and formally charged with the bombing on May 10.

Click for full size - note the crater

There are many problems with the official story of the bombing. Let's start with McVeigh's whereabouts on April 17.

McVeigh had been filmed by a security camera at a nearby McDonald's 24 minutes before the time stamped on the truck rental agreement, wearing clothes that did not match either of the men seen at Elliott's.

There is no plausible explanation of how he traveled the mile and a quarter from McDonald's to the rental agency, carless and alone as he claims, without getting soaked in the rain.

The three people interviewed agreed John Does 1 and 2 were dry. According to Stephen Jones, who has seen the interview transcripts, it took 44 days for the FBI to convince the car rental agency owner that John Doe 1 was Timothy McVeigh. And in the end they did not dare put him on the witness stand, for fear of what might happen under cross-examination.

There is also an unanswered question with regard to the truck, namely what was the Army doing with a Ryder Truck just before the Murrah blast?

Ryder Truck IN Army Compound


The biggest problem with the official story of the bombing are early news reports of the incident:

A collection of live news broadcasts documenting the Oklahoma City bombing.

2.6 MB wmv download

"'s now what we are starting to learn about the succession, or what someone obviously hoped would be a succession of explosions. The first bomb that was in the federal building did go off ... the second explosive was found and defused. The third explosive that was found and they are working on it right now ... both the second and third explosives, if you can imagine this, were larger than the first. ... It is just incredible to think that there was that much heavy artillery that was somehow moved into the downtown Oklahoma City federal building."

"...this is the work of a sophisticated group, this is a very sophisticated device, and it has to have been done by an explosives expert."

Other live news broadcasts reporting additional bombs can be heard in this 862kB mp3 file. Additional bombs are also reported in this CNN transcript and public records.

The Murrah building was not destroyed by a single truck bomb - the Eglin blast effects study and General Partin's Report prove this is the case.

Things that go BOOM in the night!

Before proceeding to the acoustical data, let me explain a little something about explosives and how people perceive them.

I work in special effects. In films, great use is made of low velocity explosives such as untamped black powder and ANFO because they are low velocity explosives. With a great whoosh and roar they belch forth with fire and smoke in a manner that has caused folks to drop their popcorn in matinees ever since sound came in.

Movies have conditioned people to expect a certain look and sound to explosions, all based on very low velocity explosives. In a stunning ironic twist, moviegoers seem to perceive the slower explosions as more powerful.

Demolition experts will tell you that high brissive or high velocity explosives actually are more powerful, as they build up a powerful shock wave. However, except for actually collapsing a structure, such explosives are unsuitable for film. The blast is over so quickly it can be missed while the film is moving between one frame and the next. There is very little visible smoke and flash, and the "crack" of a C-4 cutter charge is downright disappointing to hear.

Thus, the average person's awareness of what an explosion is supposed to look and sound like is based on the movies and low velocity explosives only. In not knowing what high velocity explosives sound like or feel like (as the shock wave moves through the earth), many people might not understand what they have heard or felt on April 19th.

With that in mind...

[The Spectrum]

Click for full size image

The Lawyer's Dictation Tape

This is the dictation tape made by a lawyer which captures the sounds of the blast which destroyed the Oklahoma Federal Building on April 19th, 1995. Note the sounds of a rattle which precedes the blast by one second. This sound is the surface wave from the ANFO Truck Bomb which arrives ahead of the airborne concussion, traveling through the Earth's surface. 4.2 seconds ahead of the start of the rattle, a "thump" is heard on the tape, overlapping the second syllable of the word "attorneys".

Events marked on the jpg file
  1. The thump at -4.2 seconds.
  2. An airborne event which arrives at the correct place to be associated with event 1, if it originates at the same location as the truck bomb itself.
  3. This marks the start of the arrival of the surface wave from the truck bomb. On the tape, this can be heard as a rattle building under the lawyer's voice. Note that unlike the lawyer's voiceprints, which show clear banding in frequency, the sounds from the truck bomb surface wave are smoothly distributed in the lower frequencies.
  4. This is the arrival of the airborne concussion from the truck bomb. Like the surface wave, this signal lacks the striations of the lawyer's voice. The most notable difference is the sudden transition to high frequency components.

Note that the Surface Wave / Air Wave delays are identical in both cases, indicating similar distances from the recording device.

When I originally heard this tape, I discarded the "pop" at the -4.2 second mark as just noise on the tape. However, when the Water Board tape (which follows) also had an artifact at the -4.2 second mark, I ran a frequency domain audio spectrogram on the lawyer's dictation tape. The spike corresponding to the pop at the -4.2 second mark is circled. The other event marks were added later. The stripe at the top is electronic noise, possibly from the dictation machine itself.

The Oklahoma Water Board Tape

At the time when the Truck Bomb exploded outside the Murrah Federal Building on April 19th, The Oklahoma Water Board was meeting in a building diagonally across the street. 4.2 seconds prior to the truck bomb blast, a loud "thump" is heard on the tape, just as the speaker finishes the phrase," are four elements that I have to..".

On this tape, the speaker pauses after the thump is heard, and just prior to the main blast, if you listen real close, other voices can be heard just starting to speak up.

What does it all mean?

From the above evidence, it is clear that an event which generated a high frequency surface wave which preceded the main truck bomb blast by 4.2 seconds. This event was recorded at two different locations at distances of 100 yards and 1/3 of a mile. Because the 4.2 second interval remains constant at both distances, theories of mechanism producing echoes are eliminated. Because the spectrogram of the lawyer's tape shows BOTH surface and airborne waves separated by 4.2 seconds from BOTH surface and airborne waves of the truck bomb, arguments of a surface/air phenomenon are invalid. Two events at the Murrah building 4.2 seconds apart produced two sets of surface/air pairs 4.2 seconds apart at the lawyer's office.

The Seismographic Records from Norman Oklahoma

These images are scans of the seismographic output from the Norman Oklahoma Z-axis recorder for April 19th and May 23rd; the bombing and the demolition respectively. This is the raw data which led Ray Brown and Charles Mankin to decide that there may have been a second explosion. It turns out that the 10 second delay is caused by differing propagation times through the layers of shale and sandstone that lie under Oklahoma City.

April 19th: The Bombing of the Murrah Building

The FAX cover logo from the Oklahoma Geological Survey

OKGS Fax Letterhead
Click for full size image

Scan of the seismographic record. Note the circle around the Murrah events.

[4/19 seismograph lorez]
Click for full size image

Circled Detail of the Murrah events.

[4/19 seismograph Murrah events]
Click for full size image

May 23rd: The Sequenced Demolition of the Murrah Building

The additional spikes on this record are caused by wind flexing the radio antenna which is used to transmit the data to the Oklahoma Geological Survey.

Seismographic record of the Murrah Building Demolition

[5/23 seismograph]
Click for full size image

Detail of the Murrah Demolition.

[5/23 Detail]
Click for full size image

Note that the 8 second long sequenced demolition of the remainder of the Murrah Building yielded a trace the same length as the original bombing. The first trace, if indeed a single explosion, should be shorter. But it isn't, suggesting that BOTH events consisted of multiple sequenced detonations over several seconds' duration.

The Murrah Building Cover-up (literally)

The minister who married my wife and I was in OK City right after the Murrah Building bomb(s) exploded, and he volunteered to help dig for survivors. He told of three very odd occurrences. In the first, he was required to show his ID six times before being allowed to help look for survivors. In the second, he confirmed the stories told by others that men in suits and ties were literally stepping over the wounded in their haste to gather up files and certain other items in the debris.

Lastly, and the oddest story of all, he told of more men in suits and ties taping plastic sheeting over portions of the building wreckage! The plastic sheeting used was very thin, could not possibly provide any mechanical support for the covered items, and seemed to serve no other purpose than to conceal the wrapped object from view. This story has also been confirmed by other witnesses.

Finally, a photo surfaced which confirms this story (see right).

Click for full size image

Note at the very right edge of the photo a large piece of the building covered in shiny black plastic, partly obscured by the flat piece of floor leaning against it. Note the ladder to get a sense of the size of the covered object.