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JFK Assassination HSCA Hearings
House Select Committee on Assassinations Chief Counsel G. Robert Blakey continues opening remarks at hearing on the assassination of U.S. President John F. Kennedy. Blakey continues remarks on findings of the Warren Commission. The discovery of three spent cartridge cases were found on the sixth floor of the Texas School Book Depository was considered convincing proof of only three shots, and the Warren Commission concluded its investigation disclosed no credible evidence that shots were fired from anywhere else. The work of the House Select Committee on Assassinations on the number of shots fired has been based almost entirely on scientific evidence. The Committee has had access to a motion film record of the assassination made by Abraham Zapruder, forensic and medical testimony, ballistic and neutron activation analysis, a trajectory reconstruction, and an analysis of a recording of sound transitions from a police motorcycle radio. The hearing will be concerned for the most part with the scientific evidence and its implications, with particular attention paid to new analysis of data previously developed in the Committee’s acoustics project, conducted by independent consultants whose findings were recently submitted to the Committee. Predominantly Caucasian adult male and female audience.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing into the assassination of U.S. President John F. Kennedy, Committee Counsel G. Robert Blakey discussing Committee attainment of acoustics analysis of a sound recording of made during the assassination in Dealey Plaza, evidence not available to the Warren Commission. A Dallas Police tape recorded the sounds of the assassination from the transmitter of a motorcycle police officer whose microphone was on. The Committee searched for the best people in the acoustics field, and contracted the firm of Bolt, Beranek, and Newman (BBN). Early testing was unsuccessful, as the Committee only had a copy of the tape. The Committee was later able to obtain the original copy of the 1963 dispatch tape, along with dictabelts that originally recorded the transmission. Dr. James E. Barger of BBN was able to locate several segments of the tape that contained “impulses” that might have been gunfire. The impulses were put through six screening tests.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Committee Chief Counsel G. Robert Blakey continuing to discuss acoustic analysis carried out on the Dallas Police audio transmission tape. Independent experts Professor Mark Weiss and Ernest Aschkenasy were brought in to review the findings of Dr. James E. Barger of Bolt, Beranek, and Newman. Weiss and Aschkenasy focused on the third shot, the one Dr. Barger thought may have come from the grassy knoll. Weiss and Aschkenasy will be available to testify at the hearing today. Blakey discusses Weiss’ credentials. Weiss was also hired by the U.S. Government to analyze U.S. President Richard Nixon’s audio tapes during the Watergate investigations.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Committee Chief Counsel G. Robert Blakey continuing to discuss acoustic analysis carried out on the Dallas Police audio transmission. Blakey discusses credentials of Ernest Aschenasy, who also assisted in the analysis of U.S. President Richard Nixon’s audio tapes during the Watergate investigation. Blakey asks to call Professor Mark Weiss and Aschenasy as witnesses. Committee Chairman U.S. Representative Louis Stokes (D-OH), seated with U.S. Representatives L. Richardson Preyer (D-NC) and Samuel L. Devine (R-OH), calls Weiss and Aschenasy as witnesses, who are sworn in.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Committee Deputy Chief Counsel Gary T. Cornwell continuing to take testimony of Professor Mark Weiss and Ernest Aschenasy on acoustic analysis of the Dallas audio transmission tape. Weiss discusses the scientific principles behind echoes and sound in recordings vs. the human ear. Weiss discusses variables in echoes in urban environments such as Dealey Plaza.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Committee Deputy Chief Counsel Gary T. Cornwell continuing to take testimony of Professor Mark Weiss and Ernest Aschenasy on acoustic analysis of the Dallas audio transmission tape. Weiss discusses reproduction of sound and echo patterns based upon sound source and listener location. Weiss discusses the scientific principles used in his analysis.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Committee Deputy Chief Counsel Gary T. Cornwell continues taking testimony of Professor Mark Weiss and Ernest Aschenasy testimony on acoustic analysis of the Dallas Police audio transmission tape from the assassination. Weiss discusses the equipment used for analyzing the tape: a large survey map of Dealey Plaza, a long graduated scale for measuring map scale, a calculator, and an oscilloscope for measuring wavelengths and plotting.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Committee Deputy Chief Counsel Gary T. Cornwell continuing to takes testimony of Professor Mark Weiss and Ernest Aschenasy on acoustic analysis of the Dallas Police audio transmission tape from the assassination. Weiss discusses the basic principles of audio analysis and echoes in Dealey Plaza, and the use and placement of microphones set to predict the echo pattern. Weiss discusses usingthe acoustic analysis of Dr. James E. Barger to become familiar with the acoustical structure of Dealey Plaza.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Committee Deputy Chief Counsel Gary T. Cornwell continuing to take testimony of Professor Mark Weiss and Ernest Aschenasy on acoustic analysis of the Dallas Police audio transmission tape from the assassination. Weiss discusses additional information needed to be gathered in addition to the acoustic analysis of Dealey Plaza by Dr. James E. Barger. Weiss says his team needed to know where the sources of sound were and have some idea of where a shooter might have been, by all indications the Grassy Knoll. Weiss says they also needed to know locations of reflective surfaces for echoes. Weiss had to know where the police motorcycle that recorded the audio was positioned, and was likely in the proximity of the microphone that picked up the strongest matching pattern in Dr. Barger’s tests-- between a shot from the Knoll and impulses on the police tape recording. Weiss says the sound velocity also needed to be determined. Weiss discusses the speed of the tape recorder being about 5 percent slow.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Committee Deputy Chief Counsel Gary T. Cornwell continuing to take testimony of Professor Mark Weiss and Ernest Aschenasy on acoustic analysis of the Dallas Police audio transmission tape from the assassination. Cornwell and Weiss discuss the shooting sound locations and the location of the police motorcycle.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Committee Deputy Chief Counsel Gary T. Cornwell asking Committee Chairman U.S. Representative Louis Stokes (D-OH) to admit and display exhibits 349, 672, and 667. Stokes admits the exhibits. Middle-aged adult Caucasian female assistant helps Professor Mark Weiss set up the exhibits for further testimony. The assistant mics Weiss and gives him a pointer stick.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Committee Deputy Chief Counsel Gary T. Cornwell continuing to take testimony of Professor Mark Weiss and Ernest Aschenasy on acoustic analysis of the Dallas Police audio transmission tape from the assassination. Weiss discusses his audio analysis of Dealey Plaza with the aid of visual displays, points out the hypothetical location of observer and shooter near the Grassy Knoll in an enlarged aerial photo. Weiss explains the directions of gunfire sounds. Middle-aged adult Caucasian female assistant steps in to reposition Weiss’ microphone. Weiss discusses sound and echo patterns in Dealey Plaza.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Professor Mark Weiss continuing to discuss acoustic analysis of Dealey Plaza via visual aids. Weiss explains visual printouts of gunshot sound waves and echoes. Weiss turns to topographic survey map of Dealey, pointing out the positions of Elm Street, the Grassy Knoll, and Microphone Number Four. Weiss points out echo points in Dealey Plaza.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Professor Mark Weiss discussing a specific echo point within the soundwave printouts from the acoustic analysis of Dealey Plaza. Committee Deputy Chief Counsel Gary T. Cornwell interrupts to ask Weiss to adjust his microphone. Young adult Caucasian male assistant adjusts Weiss’ mic. Weiss discusses the process of locating specific echo surfaces in Dealey Plaza corresponding with specific echoes recorded in the acoustic analysis.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Professor Mark Weiss discussing the scientific and mathematical processes for identifying exact echo locations of gunfire in Dealey Plaza, based on data from the acoustic analysis. Using two pins and a length of string, Weiss plots out the direction of gunfire sounds and echo points on a map of Dealey Plaza. Weiss identifies the Dallas County Records Building as one echo surface.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Professor Mark Weiss using two pins and a length of string to demonstrate the method for finding another echo surface in Dealey Plaza. Weiss says there were 22 echo paths in total found in the acoustic analysis of Dealey Plaza.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations Committee Deputy Chief Counsel Gary T. Cornwell asking Professor Mark Weiss to reconfirm and further explain the findings of the echo paths in the acoustic analysis of Dealey Plaza. Weiss simplifies his explanation of echo paths in the acoustic analysis, says the purpose of his work was to find a set of echoes that would match the impulses found on the Dallas Police audio transmission recording of President John F. Kennedy’s assassination. Weiss displays and explains a waveform chart of the Dallas Police recording, pointing out the impulses in the recording. Cornwell asks Weiss to explain why the current waveform chart on display looks different from the waveform chart from that of Dr. James E. Barger from his analysis of the original recording. Weiss says Dr. Barger’s waveforms represent the strength of the signal, whereas Weiss’ waveforms were focused on precise measurements of time-elapsed.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Professor Mark Weiss explaining the process used for predicting gunfire echo paths from the Grassy Knoll in Dealey Plaza. Using a topographical map of Dealey Plaza and a scale, Weiss demonstrates their method of determination. Weiss discusses variables in echo times and distances.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Professor Mark Weiss setting up a chalkboard and waiting for adult Caucasian female assistant to provide him with chalk. Weiss uses the chalkboard to illustrate the interval in time between the initial gunshot and an echo from different surfaces in Dealey Plaza. Weiss begins discussing moving around the microphone and rifle.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Committee Deputy Chief Counsel Gary T. Cornwell asking Professor Mark Weiss if he concluded the hypothetical shooter was not in the chosen location, or if the open microphone of the Dallas Police motorcycle was not in the right location; Weiss says this was the conclusion. Weiss says that after changing the position of the shooter and the microphone (the two variables), you start to close in on data matching the original Dallas Police audio transmission. Weiss discusses the difficulty encountered in getting the experiment data to match the data from the original police audio transmission.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Professor Mark Weiss continuing to discuss the Dealey Plaza acoustics recreation and the original Dallas Police audio transmission of Kennedy assassination. Weiss points out that a new variable needed to be added: the microphone on the Dallas Police motorcycle was in motion, so the experiment’s microphone needed to be put in motion, matching the bike's speed. Once the microphone was put in motion, the experiment produced an echo set matching the impulses on the Dallas Police audio transmission with greater accuracy.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Committee Deputy Chief Counsel asking Professor Mark Weiss if he can quantify the findings of his acoustical analysis of Dealey Plaza. Weiss uses his waveform chart to further explain data generated from his experiment. Weiss says his team focused only on what matched the noise level of gunfire and the proceeding echoes in Dealey Plaza.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Professor Mark Weiss continues explaining the findings of his acoustical analysis of Dealey Plaza. Weiss discusses the concept of binary correlation. Committee Deputy Chief Counsel Gary T. Cornwell watches on. Weiss discusses probabilities. Cornwell asks Weiss if the position of the shooter could have been moved in the experiment; Weiss says it was possible to move the shooter’s location within a five-foot radius on the Grassy Knoll but reaffirms the current position provided the best match to the original Dallas Police audio transmission.
JFK Assassination HSCA Hearings
House Select Committee on Assassinations hearing on the assassination of U.S. President John F. Kennedy, Committee Deputy Chief Counsel Gary T. Cornwell asking Professor Mark Weiss if he can identify the type of firearm that would have been fired from the Grassy Knoll based upon the Dallas Police audio transmission and acoustical analysis of Dealey Plaza. Weiss discusses the audio signature of a rifle firing a supersonic bullet. Weiss points out evidence of a supersonic shock wave on the waveform charts from the original Dallas Police audio transmission of the Kennedy assassination and the acoustical analysis of Dealey Plaza. Cornwell asks Weiss to confirm if the hypothetical shot from the Grassy Knoll was a supersonic bullet from a rifle.