Goofs

When Gates' chauffeur is in the mansion, he is not wearing a watch on any hand. But after Raven kicks him down the basement stairs and the chauffeur is trying to crawl up the stairs, he now has a watch on his left wrist. When he then calls Gates to warn him, he again is no longer wearing a watch.

While unconscious, Ellen is shown lying on the couch tied up and gagged. Her wrists and upper torso are tied, but her ankles are untied. However, after she is picked up and carried into the next room, her ankles are now bound.

When Gates discovers Graham and Raven sleeping on the train, Raven's head is on Graham's shoulder. The next shot after the one of Gates retracing his steps shows them separated.

After Raven demands Annie leave his room, he sees the kitten on the floor with the overturned condensed milk can. The saucer is not on the floor, but when the angle changes, the saucer is on the floor and the kitten is drinking from it.

The chemical formula shows fairly straightforward chemistry on page one, but page two is a meaningless jumble of letters and numbers.

When the old man is pronounced dead, two seconds later his mouth moves.

When Raven shoots through the door to kill the female witness, the slide on his 1903 model Colt pocket automatic doesn't cycle and no empty cartridge is ejected, indicating that the pistol was loaded with a low-powered blank.

When Tommy takes the ax and smashes the basement window to escape, the interior view of the window would make no more than 3 feet wide, but when he is seen smashing the window from the exterior shot, the window is at least 4 feet wide.

When Lieutenant Crane leaves the house, the car he is in is immediately heard to drive away. It would have taken him more than a few seconds to get into the car and drive away.

When Ellen is auditioning, she grabs a cigarette and turns it into a cigar, but after she hands it back you can see that it's made of rubber by the way it bounces up and down in his hand.

The "San Francisco Express" newspaper headlining the two murders at the start of the movie also has a story about a street car fire on N. Bartlett Avenue in Whitefish Bay. That is in suburban Milwaukee, Wisconsin, and would not be featured on the front page of a California newspaper.

The police don't seem interested in how Gates knows what the supposed thief Raven looks like when they were searching the train. Earlier he was chastising the police ( Lt Crane) for not capturing the thief, but there is no way he should have known what he looks like.

As Ellen and Michael leave the arcade, the shadow of a boom mic is visible on a wall behind them.

(at around 52 mins) Crane finds a playing card on the sidewalk by the police car and exclaims, "These are Ellen's; she's blazing a trail for us." First, as it's only a single card, he should have said "this is"; second, he misuses the idiom "blazing a trail" which means to clear a path. Ellen simply was "leaving a trail".