The rifle was subjected to further forensic examination at the laboratory. A palm print was discovered on part of the rifle that could only have been put there when the rifle was not fully assembled. Such a palm print could not be placed on this portion of the rifle when assembled because the wooden foregrip covers the barrel. He did not complete his investigation, however, because he was told to stop, and to hand the rifle over to FBI Agent Vince Drain, because the FBI would finish the investigation. He later did his own research, however, and concluded that the prints were Oswald's, because by then he had Oswald's prints on file.