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More than one JFK assassin?
27/03/2001 11:42 - (SA)
London - Sounds heard on police recordings from the killing of President John F. Kennedy are consistent with a shot being fired from Dallas's famed grassy knoll, according to a new scientific article.
Recordings of police radio traffic at the time of the 1963
assassination include loud noises which some investigators believe were gunfire. There has also been persistent speculation about the possibility that someone fired from the knoll in front of the president, instead of the sixth-floor window behind him used by Lee Harvey Oswald, identified by the Warren Commission as the sole assassin.
"Whatever their origin, the gunshot-like sounds occur exactly
synchronous with the shooting," says the author, D.B. Thomas, who
works for the US Department of Agriculture in Weslaco, Texas.
Thomas has a doctorate in entomology and focuses his research on
fruit fly ecology, according to the USDA.
His article was published in Science & Justice, the journal of
Britain's Forensic Science Society.
Kennedy was killed on November 22, 1963, as his motorcade wound past Dealey Plaza in Dallas.
The 1964 report by an official commission headed by Earl Warren,
then chief justice of the Supreme Court, concluded that at least two shots were fired at Kennedy, both by Oswald from the Texas School Book Depository building, located behind the motorcade.
The commission rejected the suggestion that anyone other than
Oswald had fired. "There is no credible evidence that the shots
were fired from the Triple Underpass, ahead of the motorcade, or
from any other location," the Warren Commission said. The underpass is near the grassy knoll.
The police recordings have a number of loud noises which might be
identified as gunfire. Thomas says there are five sounds "that have the acoustic waveform of Dealey Plaza gunfire".
"One of the sounds matches the echo pattern of a test shot fired
from the grassy knoll," he wrote.
Thomas' analysis is the latest done on the recorded police radio
transmissions. The transmissions were on two channels: One, for
routine calls, was preserved on a sound-activated Dictaphone belt. A second frequency, dedicated to the motorcade, was recorded on a sound-activated disc machine, Thomas wrote.
In 1978, the House of Representatives Select Committee on
Assassinations hired a Massachusetts agency to analyze the police
recordings. Specialists fired test shots in Dealey Plaza, with 36
microphones placed in various locations to examine the possibility of a shot from the knoll.
The committee concluded that sounds heard on an open microphone,
apparently on a police motorcycle, could be shots from the grassy
knoll.
The Computer Sciences Department of City University, New York, also examined the recordings and concluded the sound could be a shot.
In 1980, the Justice Department asked the National Research Council to analyse the data again. That review concluded there was a 78 percent probability that at least one of the bangs was a gunshot from the knoll. But the review also concluded that the suspect noises were a minute later than the time Kennedy was shot.
Thomas argues that the National Research Council reached that conclusion because it erred in its attempts to synchronise the two police recordings.
He says the council used a phrase - "hold everything secure" -
which is heard on both tapes - to synchronise the timing of events. But he said that phrase was a poor marker because problems with one of the tapes make it unclear.
Thomas worked from another, clearer bit of talk from Dallas
patrolman S.Q. Bellah, who is heard asking: "You want me to hold
this traffic on Stemmons until we find out something, or let it
go?"
That phrase appears 180 seconds after the suspected shots on one
recording, and 171 seconds later on the other recording. Allowing
for a difference in tape speed of 5 percent, Thomas says the
recordings match.
Thomas could not be reached for comment at his office on Monday.
- AP
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