When the parents of celebrated boy violinist Caesar Paul report the boy missing, they state that he has a concert tonight. But when he is found later on that same day, they now state that the concert is tomorrow.
When Butch goes to Norma's apartment, the music comes on the radio as soon as he touches it - and even before the "click" of the power/volume knob is heard. Radios of the time used vacuum tubes that needed to warm up for a few seconds before sound would come on.
When Joe shows Kingman's missing flyer to Butch Burton, the flyer reads June 21. Joe then informs Butch that Kingman disappeared a couple of days ago, therefore, indicating the present date must be June 23. Shortly after that same day, another missing person's case regarding Caesar Paul a celebrated boy violinist is reported by the boy's parents. They tell Capt. Webb that he has a sold-out concert tonight. Later on Butch passes a promotional poster and it reads that the concert is August 21. The two missing cases creates a conflict as to what the present day is; it has to be either June 23 or August 21 but it can't be both.
When Butch passes a poster announcing the concert of Caesar Paul, it reads Wednesday, August 21. However, this took place in the year 1933 as evident by the telegram stating that Norma Williams Roberts murdered her husband ten days ago on June 22, 1933. In the year 1933 August 21 fell on a Monday, therefore, the day of Wednesday on the poster is an error.
Butch tells Capt. Webb he found Caesar on a roof on 10th Avenue, which is on the west side of Manhattan. However from shots from the roof, the Manhattan Bridge is visible, which spans the East River from Lower Manhattan to Brooklyn. The bridge is too close for the rooftop to be on 10th Avenue.