JFK: Nuevos datos sobre una tragedia

The assassination of President John F. Kennedy on November 22, 1963, was a tragic event in American history. Many questions still linger about the young president’s death, even though more than 50 years have passed. What really happened in Dealey Plaza in downtown Dallas, Texas that day? Did Lee Harvey Oswald fire the bullet from the sixth floor of the former Texas School Book Depository (TSBD) alone, or did a second gunman fire a shot from the “grassy knoll”, a small sloping hill inside Dealey Plaza? For the first time ever, modern technology has been applied to investigate the Warren Commission’s conclusion of where the fateful shot originated. The Leica ScanStation P20 plays a valuable role in a new, state-of-the-art shooting reconstruction and helps forensic specialists resolve some of the mystery.

大多数人仍然认为阴谋是总统去世的背后，并坚信这不是一个人的工作。现代弹道和技术可以证明这是错误的吗？50年前，那天在Dealey Plaza发生了什么？在Leica Geosystems的ScanStation P20的帮助下，弹道专家Michael和Luke Haag着手确定“ Cold Case JFK”中的“单子弹理论”是否可以，这是PBS提出的特殊NOVA系列的一部分。

The rifle and the bullet
“Creating an accurate 3D laser representation of the crime scene using the Leica ScanStation P20 made documenting the precise location of the gun as well as the primary point of bullet impact possible. Using the Leica Cyclone software for bullet path reconstruction, we recreated a line segment for the original trajectory and any secondary trajectories,” says Michael Haag. For the Nova documentary, Michael Haag and Tony Grissim of Leica Geosystems, a technical advisor for the Firearms and Tool Mark Examiners, collected laser scan data to create an entire 3D representation of Dealey Plaza and of the sixth floor of the TSBD. This representation, along with Doppler radar and high speed videography, provided accurate information that was previously unavailable to investigators.

“当我想看看新的阴谋论about what happened, I don’t have to go back to the scene; I can just go to my computer and start clicking on scan data to look at distances and angles, and compare those points and angles to what I know occurred ballistically,” Michael says.

The Haags also recreated materials similar to the density and resistance of human muscle tissue to test the bullet’s impact and exit velocity, and to test its strength and stability. Could it pass through two people, a car seat and bone material and remain intact? The 3D laser maps were analysed with the tests made to this recreated material using the same type of bullets and rifle used in the shooting. This newly acquired data plus the now public documents and evidence that was hidden for the last 50 years helped Michael and Luke Haag to prove that the “single bullet theory” could have been reality. It was possible to load, aim and fire two bullets within these few seconds and destroy so much. Luke Haag says, “It’s a very clear picture. There was plenty of time to shoot all three shots from when the car turned the corner into Elm. We tried replicating it ourselves and could do so many times. We ruled out the conspiracy hypothesis, the shots from the grassy knoll … two shooters.”

Michael Haag has been using 3D scanning technology from Leica Geosystems for nearly a decade to reconstruct shooting incidents. His experience provides key insights on why an increasing number of law enforcement agencies and crime scene investigators have begun to rely on this valuable tool. “It’s a way of documenting crimes scene more thoroughly, more completely than we have ever had the capability to do,” says Michael. “We can re-examine the cases from our computers as new hypotheses appear, over and over, from new angles with new measurements, calculations – it’s all right there. As a forensics scientist you try to rule out hypotheses, not go into it with the idea that you want to prove something. Physical evidence always supports the truth of the matter.”

Written by Christine L. Grahl