A new analysis by a Dartmouth College professor concludes that the infamous photograph of Lee Harvey Oswald holding a rifle in his backyard would have been nearly impossible to fake.

Oswald, who was shot to death days after being charged with assassinating President John F. Kennedy, claimed the photo of him holding a rifle in one hand and Marxist newspapers in the other had been doctored. Over the years, others have pointed out what appear to be inconsistent lighting and shadows in the image.

But Hany Farid of the Neukom Institute for Computational Science used digital forensic tools to analyze the photo. He says the shadows are exactly where they should be and it's extremely unlikely the photo is a fake.