Washington: A computer scientist has unearthed new evidence to show that a well-known photograph of Lee Harvey Oswald, John F. Kennedy`s alleged killer, was not fake.
Hany Farid, a pioneer in digital forensics at Dartmouth College, analysed an iconic image of Oswald, pictured in a backyard setting, holding a rifle in one hand and Marxist newspapers in the other.
"It is highly improbable that anyone could have created such a perfect forgery with the technology available in 1963," said Farid. With no evidence of tampering, he concluded that the incriminating photo was authentic.
Oswald and others claimed that the incriminating photo was fake, noting the seemingly inconsistent lighting and shadows.
After analysing the photo with modern-day forensic tools, Farid said the photo almost certainly was not altered.
"If we had found evidence of photo tampering, then it would have suggested a broader plot to kill JFK," said Farid, who is also the director of the Neukom Institute for Computational Science at Dartmouth.
Farid added that federal officials long ago said this image had not been tampered with, but a surprising number of sceptics still assert that there was a conspiracy.
Farid and his team have developed a number of digital forensic tools to determine whether digital photos have been manipulated, and his research is often used by law enforcement officials and in legal proceedings.
The tools can measure statistical inconsistencies in the underlying image pixels, improbable lighting and shadow, physically impossible perspective distortion, and other artefacts introduced by photo manipulators.
The play of light and shadow was fundamental in the Oswald photo analysis. At a casual glance, the lighting and shadows in the Oswald photo appear to many to be incongruous with the outdoor lighting, says a Dartmouth release.
To determine if this was the case, Farid constructed a 3-D model of Oswald`s head and portions of the backyard scene, from which he was able to determine that a single light source, the sun, could explain all of the shadows in the photo.
The study is slated for publication in Perception.
Bureau Report
