Original 35mm black and white negative taken by Dallas Times Herald staff photographer William Allen Friday afternoon after the assassination - between 12:30 and 1 p.m. This image shows a Dallas Police officer, holding a shotgun, standing in the street at the intersection of Houston and Elm streets outside the Texas School Book Depository. The Dal-Tex building and the County Records Building are visible behind him; the Book Depository building is not in the picture.