When Doris told Mason about the service on Haywood's car she said the sticker showed 5700 miles. In court it was stated the sticker showed 5621 miles.
Even in 1958, the police would perform a blood alcohol test before filing such serious charges. Smelling alcohol in the car is not proof that the driver was drunk.
In the opening minutes Berger and Hanlon talk about hating to be the ones notifying the dead truck driver's family. It would be the police handling that, not the district attorney's office.
While on the witness stand, Jerry Heywood says Fresno is 300 miles from Los Angeles. Though the modern distance from Fresno to LA is almost exactly 221 miles, not the 300 stated by the witness, this was not a goof at the time. Interstate Route I-5, which shortens the distance to 221 miles did not exist until 1964. Highway CA-33 would have been used when this was filmed, which at 291 miles is close enough to 300 that most people would probably just say 300.
Claire Olger describes the dark-haired man who gives her a ride as having blonde hair.
In the newspaper with "Claire Olger's" photo, the second line of the article reads that a "soldier," and not a "trucker," was killed in the vehicle accident.
The newspaper story of the Greeley murder has text below the headline which is irrelevant to the murder. Also, the victim's name is spelled "Greely", not the spelling used in the credits.
(at around 18 mins) As Perry and Paul Drake enter a hallway and approach a hotel room door, just before looking through a transom window, a part of the sound-man's rig is clearly visible at the bottom right for 15 seconds.