According to Hitchcock, a series of shots with Arbogast going up the stairs in the Bates house before he is stabbed were done by assistant director Hilton A. Green, working with storyboard artist Saul Bass' drawings only while Hitchcock was incapacitated with the common cold. However, upon viewing the dailies of the shots, Hitchcock was forced to scrap them. He claimed they were "no good" because they did not portray "an innocent person but a sinister man who was going up those stairs". Hitchcock later re-shot the scene, though a little of the cut footage made its way into the film. Filming the murder of Arbogast proved problematic owing to the overhead camera angle necessary to hide the film's twist. A camera track constructed on pulleys alongside the stairway together with a chairlike device had to be constructed and thoroughly tested over a period of weeks.