When "Walter" and his mother pose for the news picture outside the train, the policewoman who escorted "Walter" is standing directly behind them and would have appeared in the background of the picture. At the trial, the picture shows mother and "son" but the policewoman is nowhere in the shot.
First when Christine is thrown in her cell, the hatch behind the barred window is shut with force. Later, when Christine is watching Carol being brought back to her cell, the cell doors don't have hatches at all.
When the 15-year-old accomplice stops digging and rolls on the floor, his overalls are hanging. When the officer tries to pull him up, his overalls are normal.
When Sanford Clark is first looking at the photographs of the missing boys, the picture on the bottom of the stack is of a nine-year-old boy. When he eventually gets to the final picture, the age written on the photo is 10.
When the police car pulls up to the Collins house to take down the missing child report, the first policeman steps onto the tree lawn and starts talking to Christine Collins. When the camera angle changes to a view from across the street, the policeman is suddenly standing on concrete.
Rev. Gustav and Mrs. Collins meet at his home. The walls in the background are full of religious images, including St. Anthony of Padua holding the child Jesus. No Protestant minister, especially in the 1930s, would have an image of a Catholic saint in their home; it would be considered 'Popish idolatry'.
The night before he disappears, Walter expresses his disappointment about missing a broadcast of "Amos 'n' Andy." The first "Amos 'n' Andy" broadcast was on March 19, 1928, 10 days after Walter disappeared.
On March 9, 1928, Christine says they might see The Mysterious Airman (1928) the next day. That movie wasn't released until June 1, 1928.
The scene depicting Vancouver in September shows snow-capped peaks in the distance. At that time of year, last year's snowpack would have completely melted during the summer and not be snowy again for several months.
Twice during the film, Christine mentions that the boy pretending to be Walter is three inches shorter than her real son, but when she testifies at the hearing, she says the difference was four inches. However, this may have been a conscious or unconscious exaggeration on her part in order to stress the difference to the court; the difference in inches was not an exact measurement.
The very last shot is mainly CGI. There are a lot of pedestrians who cross the street and just disappear behind lamp posts or walk through cars.
In the beginning, as the electric tram-car (streetcar) goes by, there are no overhead cables; the car is running without any power. Shortly after, a downward view of the street shows two trams; again, there are no power lines - the car's pantographs are not connected to anything.
Rev. Gustav is a Presbyterian minister, but the arrangement of the deep chancel area in his church is not a Presbyterian layout. It was likely filmed at an Episcopal church.
The last scene shows an L.A. street. An old-style traffic post with a GO signal is on the right. Cars come and go as the credits roll, but the signal never changes to STOP.
When Christine measures Walter at the beginning of the movie there are several 'height' marks already on the door frame, about six to seven inches apart (again seen when measuring Arthur).
Given that boys of Walter's age generally grow an average of two inches a year, this means that Christine was only measuring and marking his height about every three to four years.
Given that boys of Walter's age generally grow an average of two inches a year, this means that Christine was only measuring and marking his height about every three to four years.
Detective Ybarra uses the term "serial killer," coined by FBI Special Agent Robert K. Ressler in the 1970s.
A scene set in 1928 features electro-convulsive therapy (electroshock therapy). Electroconvulsive therapy was first used on humans in 1937 by Italian doctor Ugo Cerletti.
Mrs. Collins tells Walter she's left him a "sandwich in the fridge." In 1928, the word "fridge" was very new and restricted to the East Coast. A Californian would have said, "icebox."
A simple lunch for two in a cheap diner comes to two dollars, about $28 in 2008. In 1928, the sandwiches and drinks shown would not have cost more than 50 cents.
Jeffrey Donovan's left ear is pierced, which was not acceptable for a police officer anywhere in 1928.
As Christine steps on the train to go see Gordon Northcott in prison, two blasts from a diesel locomotive "horn" can be heard. Trains at the time were equipped with steam locomotives which have a very distinctly different "whistle" sound from that of a diesel locomotive "horn".
When Detective Lester Ybarra and Sanford Clark arrive back at the ranch to dig for the remains, the Steadicam operator and other crew members are visible in the reflection of the rear left window of the car as Ybarra opens the door for Clark to exit.
A camera shadow is present three times in the bottom left-hand corner of the screen in the wide shots of three detectives as they watch Sanford Clark dig. The first time it can be seen is in the shot where Detective Lester Ybarra tells Sanford to dig.
During Walter's, David's, and Jeffery's escape, just after Sanford Clark says, "They're not in there" and just before Northcott says, "Get into the car!", the camera operator's shadow is visible for a few frames in the left-hand corner of the frame just before he pans it to follow Clark as he runs to the car.
A telephone caller tells Christine to go to the Lincoln Heights precinct. Police stations in California have never been known as precincts. The term precinct is limited mainly to police stations in New York, Boston, and Chicago.
Only one small Birney Red Car (from the Orange Empire Trolley Museum) was used. In reality, mostly yellow streetcars and bigger Red Cars would be seen downtown. The weak streetcar gong heard is not the deeper sonorous one commonly heard in LA.
Christine mentions her husband ran away because he couldn't handle the responsibilities of being a father. In real life, he was serving a sentence for armed robbery. However, she may have told Walter this to protect him from the truth about his father.
Reverend Gustav Briegleb pronounces "Los Angeles" with a soft "g". In the 1920s, most Californians used a hard "g" (like in the word "angle"). It can be heard in movies as late as the 1950s. Non-natives often said "anjeleez." When Easterners started pouring into the city later, the compromise "anjeliss" came into being.
Several times when referencing the Wineville crime scene, officers refer to the location as "...up in Wineville". leading one to believe it was north of the city. Wineville (Mira Loma) is some 35 miles ESE of Los Angeles and should be referred to as being "...out in Wineville".