Dictabelt evidence relating to the assassination of John F. Kennedy

The Dictabelt evidence relating to the assassination of John F. Kennedy comes from a Dictabelt

Dictabelt

The Dictabelt or Memobelt was a form of recording medium introduced by the American Dictaphone company in 1947. It used a type of "Write Once - Read Many" medium consisting of a thin, plastic belt 3.5" wide that was placed on a cylinder and spun like a tank tread. The needle would then move slowly...

recording from a microphone stuck in the open position on a motorcycle police officer's radio when John F. Kennedy

John F. Kennedy

John Fitzgerald "Jack" Kennedy , often referred to by his initials JFK, was the 35th President of the United States, serving from 1961 until his assassination in 1963....

, 35th President of the United States

President of the United States

The President of the United States of America is the head of state and head of government of the United States. The president leads the executive branch of the federal government and is the commander-in-chief of the United States Armed Forces....

was assassinated

John F. Kennedy assassination

John Fitzgerald Kennedy, the thirty-fifth President of the United States, was assassinated at 12:30 p.m. Central Standard Time on Friday, November 22, 1963, in Dealey Plaza, Dallas, Texas...

in Dallas, Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

on November 22, 1963. Many aspects of his assassination have been investigated, and the less well-known recording, made by a then-common Dictaphone dictation machine that recorded sounds in grooves pressed into a thin celluloid

Celluloid

Celluloid is the name of a class of compounds created from nitrocellulose and camphor, plus dyes and other agents. Generally regarded to be the first thermoplastic, it was first created as Parkesine in 1862 and as Xylonite in 1869, before being registered as Celluloid in 1870. Celluloid is...

belt, gained prominence among Kennedy assassination conspiracy theorists starting in 1978.

The recording was made from Dallas police radio channel 1, which carried routine police radio traffic (channel 2 was reserved for special events, such as the presidential motorcade

Motorcade

A motorcade is a procession of vehicles. The term motorcade was coined by Lyle Abbot , and is formed after cavalcade on the false notion that "-cade" was a suffix meaning "procession"...

). The open-microphone portion of the recording lasts 5.5 minutes, and begins about 12:29 p.m. local time, about a minute before the assassination at 12:30 p.m. Verbal time stamps were made periodically by the police radio dispatcher and can be heard on the recording.

House Select Committee on Assassinations

In December 1978, the House Select Committee on Assassinations (HSCA) had prepared a draft of its final report, concluding that Lee Harvey Oswald

Lee Harvey Oswald

Lee Harvey Oswald was, according to four government investigations,These were investigations by: the Federal Bureau of Investigation , the Warren Commission , the House Select Committee on Assassinations , and the Dallas Police Department. the sniper who assassinated John F...

had acted alone as the assassin. However, after evidence from the Dictabelt recording was made available, the HSCA quickly reversed its conclusion and declared that a second gunman had fired the third of fourth shots heard. G. Robert Blakey

G. Robert Blakey

George Robert Blakey is an American attorney and law professor. He is best known for his work in connection with drafting the Racketeer Influenced and Corrupt Organizations Act and for scholarship on that subject.-Education and family:Blakey graduated from the University of Notre Dame in 1957,...

, chief counsel of the HSCA, later said, "If the acoustics come out that we made a mistake somewhere, I think that would end it." Despite serious criticism of the scientific evidence and the HSCA's conclusions, speculation regarding the Dictabelt and the possibility of a second gunman persisted.

Investigators compared "impulse patterns" (suspected gunshots and associated echos) on the Dictabelt to 1978 test recordings of Carcano

Carcano

Carcano is the frequently used name for a series of Italian bolt-action military rifles and carbines. Introduced in 1891, this rifle was chambered for the rimless 6.5x52mm Mannlicher-Carcano Cartuccia Modello 1895 cartridge. It was developed by the chief technician Salvatore Carcano at the Turin...

rifles fired in Dealey Plaza

Dealey Plaza

Dealey Plaza , in the historic West End district of downtown Dallas, Texas , is the location of the assassination of John F. Kennedy on November 22, 1963...

from the sixth floor of the Texas School Book Depository

Texas School Book Depository

The Texas School Book Depository is the former name of a seven-floor building facing Dealey Plaza in Dallas, Texas . Located on the northwest corner of Elm and North Houston Streets, at the western end of downtown Dallas, its address is 411 Elm Street. The building is notable for its connection to...

and from a stockade fence on the grassy knoll forward and to the right of the location of the presidential limousine. On this basis, the acoustics firm of Bolt, Beranek and Newman concluded that impulse patterns 1, 2, and 4 were shots fired from the Depository, and that there was a 50% chance that impulse pattern 3 was a shot from the grassy knoll. Acoustics analysts Mark Weiss and Ernest Aschkenasy, of Queens College, reviewed the BBN data and concluded that "with the probability of 95% or better, there was indeed a shot fired from the grassy knoll."

Dr. James E. Barger, of Bolt, Beranek and Newman, testified to the HSCA that his statistical analysis of the impulse patterns captured on the Dallas police recordings showed that the motorcycle with the open microphone was approximately "120 to 138 feet" behind the presidential limousine at the time of the first shot. When the HSCA asked Weiss about the location of the motorcycle with the open microphone—"Would you consider that to be an essential ingredient in the ultimate conclusion of your analysis?"—Weiss answered, "It is an essential component of it, because, if you do not put the motorcycle in the place that it is [at]—the initial point of where it was receiving the [sound of the gunfire]—, and if you do not move it at the velocity at which it is being moved on paper in this re-creation, you do not get a good, tight pattern that compares very well with the observed impulses on the police tape recording."

The HSCA, using an amateur film shot of the motorcade, concluded that the recording originated from the motorcycle of police officer H. B. McLain, who later testified before the committee that his microphone was often stuck in the open position. However, McLain did not hear the actual recording until after his testimony, and upon hearing it he adamantly denied that the recording originated from his motorcycle. He said that the other sounds on the tape did not match his movements. Sirens are not heard on the tape until more than two minutes after what is supposed to be the sound of the shooting; however, McLain accompanied the motorcade to Parkland Hospital

Parkland Memorial Hospital

Parkland Memorial Hospital is a hospital located at 5201 Harry Hines Boulevard, just west of Oak Lawn in Dallas, Texas . It is the main hospital of the Dallas County Hospital District and serves as Dallas County's public hospital.- History :The original hospital opened in 1894 in a wooden...

immediately after the shooting, with sirens blaring the entire time. When the sirens are heard on the Dictabelt recording, they rise and recede in pitch (the Doppler effect

Doppler effect

The Doppler effect , named after Austrian physicist Christian Doppler who proposed it in 1842 in Prague, is the change in frequency of a wave for an observer moving relative to the source of the wave. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from...

) and volume, as if passing by. McLain also said that the engine sound was clearly from a three-wheeled motorcycle, not the two-wheeler that he drove: "There's no comparison to the two sounds."

Other audio discrepancies also exist. Crowd noise is not heard on the Dictabelt recording, despite the sounds generated from the many onlookers along Dallas's Main Street and in Dealey Plaza (crowd noises can be heard on at least ten channel-2 transmissions from the motorcade). Someone is heard whistling a tune about a minute after the assassination.

Four of the twelve HSCA members dissented to the HSCA's conclusion of conspiracy based on the acoustic findings, and a fifth thought a further study of the acoustic evidence was "necessary".

Criticism

Richard E. Sprague, an expert on photographic evidence of the assassination and a consultant to the HSCA, noted that the amateur film the HSCA relied on showed that there were no motorcycles between those riding alongside the rear of the presidential limousine and H.B. McLain's motorcycle, and that other films showed McLain's motorcycle was actually 250 feet behind the presidential limousine when the first shot was fired, not 120 to 138 feet. No motorcycle was anywhere near the target area.

The adult magazine Gallery
Gallery (magazine)
Gallery is a men's magazine begun by Montcalm Publishing in 1972. It is one of the more popular "skin" magazines that arose on the Playboy magazine pattern in the 1970s...

published a flexi disc

Flexi disc

The flexi disc is a phonograph record made of a thin, flexible vinyl sheet with a molded-in spiral stylus groove, and is designed to be playable on a normal phonograph turntable...

of the Dictabelt recording in its July 1979 issue . Ohio

Ohio

Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...

rock drummer Steve Barber listened to that recording repeatedly and heard the words "Hold everything secure" at the point where the HSCA had concluded the assassination shots were recorded. However, those words were spoken by Sheriff Bill Decker about a minute after the assassination, so the shots could not be when the HSCA claimed.

After the FBI

Federal Bureau of Investigation

The Federal Bureau of Investigation is an agency of the United States Department of Justice that serves as both a federal criminal investigative body and an internal intelligence agency . The FBI has investigative jurisdiction over violations of more than 200 categories of federal crime...

disputed the validity of the acoustic evidence, the Justice Department paid for the National Academy of Sciences

United States National Academy of Sciences

The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...

to review it. The National Academy of Sciences is a U.S. corporation operating with a Title 36 congressional charter.

A panel of scientists headed by Dr. Norman Ramsey issued a report in 1982 which agreed with Barber and determined that there was no compelling evidence for gunshots on the recording and that the HSCA's suspect impulses were recorded about a minute after the shooting happened.

Dr. Barger, the HSCA's acoustics expert, when asked about this discovery and the NAS analysis, replied,

Barber discovered a very weak spoken phrase on the DPD Dictabelt recording that is heard at about the time of the sound impulses we concluded were probably caused by the fourth shot. The NAS Committee has shown to our satisfaction that this phrase has the same origin as the same phrase heard also on the Audograph recording. The Audograph recording was originally made from the channel 2 radio. The common phrase is heard on channel 2 about a minute after the assassination would appear, from the context, to have taken place. Therefore, it would seem . . . that the sounds that we connected with gunfire were made about a minute after the assassination shots were fired. Upon reading the NAS report, we did a brief analysis of the Audograph dub that was made by the NAS Committee and loaned to us by them. We found some enigmatic features of this recording that occur at about the time that individuals react to the assassination. Therefore, we have doubt about the time synchronization of events on that recording, and so we doubt that the Barber hypothesis is proven. The NAS Committee did not examine the several items of evidence that corroborated our original findings, so that we still agree with the House Select Committee on Assassinations conclusion that our findings were corroborated

Donald Thomas rebuttal

An analysis published in the March 2001 issue of Science & Justice
Science & Justice
Science & Justice is a peer-reviewed academic journal of forensics published by Elsevier on behalf of the Forensic Science Society and the International Society for Forensic Genetics. The journal was established in 1960 as the Journal of the Forensic Science Society and obtained its current name in...

by Dr. Donald B. Thomas used a different radio transmission synchronization to put forth the claim that the National Academy of Sciences panel was in error. Thomas' conclusion, very similar to the HSCA conclusion, was that the gunshot impulses were real to a 96.3% certainty. Thomas presented additional details and support in the November 2001 and September and November 2002 issues.

Further analysis

In 2003, an independent researcher named Michael O'Dell reported that both the National Academy and Dr. Thomas had used incorrect timelines because they assumed the Dictabelt ran continuously. When corrected, these showed the impulses happened too late to be the real shots even with Thomas's alternative synchronization. In addition, he showed that, due to a mathematical misunderstanding and the presence of a known impulse pattern in the background noise, there never was a 95% or higher probability of a shot from the grassy knoll.

A November 2003 analysis paid for by the cable television channel Court TV concluded that the gunshot sounds did not match test gunshot recordings fired in Dealey Plaza any better than random noise. In December 2003, Thomas responded by pointing out what he claimed were errors in the November 2003 Court TV analysis.

Digital restoration

In 2003, ABC News

ABC News

ABC News is the news gathering and broadcasting division of American broadcast television network ABC, a subsidiary of The Walt Disney Company...

aired the results of its investigation on a program called Peter Jennings Reporting
Peter Jennings Reporting
Peter Jennings Reporting was a continuing series of documentaries produced and hosted by the late ABC News anchor Peter Jennings that aired on ABC. Many of these documentaries were produced by Peter Jennings's production company, PJ Productions, and are currently distributed in DVD format by Koch...

: The Kennedy Assassination: Beyond Conspiracy. Based on computer diagrams and recreations done by Dale K. Myers

Dale K. Myers

Dale K. Myers is a computer animator, author, and John F. Kennedy assassination researcher. He was honored in 2004 with an Emmy Award from the National Academy of Television Arts and Sciences for his computer animated recreation of the Kennedy assassination featured in ABC News' 40th anniversary...

, it concluded that the sound recordings on the Dictabelt could not have come from Dealey Plaza, and that Dallas Police Officer H.B. McLain was correct in his assertions that he had not yet entered Dealey Plaza at the time of the assassination.

In the March, 2005 issue of Reader's Digest
Reader's Digest
Reader's Digest is a general interest family magazine, published ten times annually. Formerly based in Chappaqua, New York, its headquarters is now in New York City. It was founded in 1922, by DeWitt Wallace and Lila Bell Wallace...

, it was reported that Carl Haber and Vitaliy Fadeyev were assigned with the task of digitally restoring Dictabelt 10 by Leslie Waffen from the National Archives. Their method consisted of using sensors to map the microscopic contours of the tracks of old sound recordings without having to play them using a stylus, which would further degrade the sound. Dictabelt 10 was worn from countless playings and cracked due to improper storage. By 2010 digital restoration of the Dictabelt seemed a more distant prospect, with both funding and final approval for the project unlikely to be secured in the near future.

Possible origins

Left unanswered by the professional analyses was the question of whose open microphone captured the sounds recorded on the Dictabelt, if not Officer H.B. McLain. Jim Bowles, a Dallas police dispatcher supervisor in November 1963, and later Dallas County Sheriff, believes it originated from a particular officer on a three-wheeled motorcycle stationed at the Dallas Trade Mart

Dallas Market Center

Dallas Market Center, located along Stemmons Freeway in Dallas, Texas , sits on of land and spans more than . Dallas Market Center is the international home of the lighting industry, a leader in home décor and the national home of the floral and Christmas industries.- The campus :The...

, the original destination of President Kennedy's motorcade, along the same freeway to Parkland Hospital

Parkland Memorial Hospital

, which would account for the sound of sirens rushing by. McLain himself believes that it was from a different officer on a three-wheeler near the Trade Mart, who was known for his whistling. When interviewed by author Vincent Bugliosi

Vincent Bugliosi

Vincent Bugliosi is an American attorney and author, best known for prosecuting Charles Manson and other defendants accused of the Tate-LaBianca murders. His most recent books are Reclaiming History: The Assassination of President John F. Kennedy , The Prosecution of George W...

, the officer acknowledged that his microphone could have been stuck in the open position (he did not recall hearing any transmissions for several minutes), and could later have become unstuck after he followed the motorcade to Parkland Hospital.