The Lee Harvey Oswald backyard photos: real or fake?

Ever since the assassination of US President Kennedy, numerous theories have circulated purporting that Lee Harvey Oswald, the accused assassin, acted as part of a larger criminal conspiracy. It has been suggested, for example, that incriminating photographs of Oswald were manipulated, and hence evidence of a broader plot. Specifically, it has been argued that the lighting and shadows in these photos are physically impossible. Because the visual system is often unable to reliably judge 3-D geometry and lighting, a detailed 3-D analysis of the Oswald photos to determine if claims of tampering are warranted.