Goofs

As Johnny enters the police station, the clock on the far wall reads 9:20. Seconds later, as Johnny walks into another room, a clock above the doorway behind him says 7:20.

When Johnny gets off the school bus to go in the police station the clock in the main lobby reads 9:40. When he walks in the room leading to his father's office the clock reads 8:40

When the Zodiac is narrating his letter after the Chief of Police invites him to write with more details of the earlier murders, his narration leaves out the word "very" before "very happy to supply even more material." that appears in the letter that he is narrating.

Johnny gets off the school bus to go into the police station and the time is 9:40. 9:40 am is too early to be getting out of school.

Crime scene tape at first murder scene is off period. The yellow "police line do not cross" screen printed plastic tape was not in use until the 80's.

In a early setting after the first murders, Inspector Matt returns to the crime scene and is holding a Mag-Lite flashlight. While the flashlight became the number one flashlight of all police departments it wasn't offered for sale till 1979. Several years after the first Zodiac murders.

The school bus used for the Vallejo School District has Budd wheels on the front axle. Trucks and buses for this period had split-ring Dayton wheels. Budd wheels would not become commonplace on school bus chassis until the late 70's.

At the beginning of the scene where Inspector Parish is questioning Patsy (a waitress) in the restaurant, a late 20th Century-style security camera is seen over the counter.

During the stakeout, when the police surround the Mercury, there is a camera shot that is from the back seat, over the driver's right shoulder. In the upper left corner of the windshield, there is a clear plastic Valvoline oil change sticker. These stickers were not in existence in 1968.