In the immediate aftermath of the shooting, police officers and spectators ran to the grassy knoll, from where some witnesses believed the shots had originated, but no sniper was found. The Warren Commission concluded that Lee Harvey Oswald was the sole shooter, and that he had shot Kennedy from the Texas School Book Depository. Conspiracy theorists, however, speculate that there was an assassin behind the wooden picket fence on top of the grassy knoll. For her part, Moorman told Larry Sabato that she did not see anything out of the ordinary behind the fence and that she remained unconvinced that a second shooter was revealed in her photograph. Moorman's photograph was not included in the Warren Commission's 1964 report or its supporting documents. Moorman stated that she had been invited to provide testimony to the Commission, but asked for a postponement after injuring her ankle, and was not contacted again. In the late 1970s, the House Select Committee on Assassinations (HSCA)—which concluded that there was a second assassin on the grassy knoll based on now discredited acoustic evidence—deemed the photo of interest to its investigation. With the unaided eye, the HSCA photographic evidence panel could find no figures in the shadowed background. The HSCA then sent a negative version of the Moorman photo to the Rochester Institute of Technology (RIT) for enlargement, enhancement, and analysis. The RIT report found no evidence of human forms anywhere in the background, and the specific area behind the stockade fence was deemed to be so underexposed that it was impossible to glean any information from it. The HSCA concluded that if the Moorman photo "did not contain images that might be construed to be a figure behind the fence, it would be a troubling lack of corroboration for the acoustical analysis". The examined photo was the original copy, which had greatly degraded by that point. Photograph enhancement Gary Mack In 1983, Gary Mack obtained an 8x10 inch UPI copy of the Mary Moorman photograph of higher quality than the degraded original. The curator of the Sixth Floor Museum at Dealey Plaza (the former Texas School Book Depository), Mack was described by skeptic Vincent Bugliosi as one of the few respected Kennedy assassination conspiracy theorists. After noticing what he thought was a human face in the shadowed background, Mack contacted Jack White—a friend and darkroom technician—to study the photograph. Upon enhancement, they identified an individual