Near the end of the film, Dave Bannion has an altercation with his brother-in-law's old army buddy in the stairwell. When he enters the apartment a second later, the sleeves of his suit are suddenly rolled up.
In the opening scene, after Duncan shoots himself, his hand and the gun fall to the desk onto an envelope and right next to his badge. When the camera angle changes, only the barrel of the gun is on the envelope, and it's a few inches from the badge.
When Bannion (Glenn Ford) fights with Larry Gordon (Adam Williams) in Gordon's hotel room, Gordon's revolver is first seen in the centre of the desk, behind Gordon. When Bannion picks-up the revolver, it is near the right-hand edge of the desk. This move is probably intentional - to allow Bannion to get the revolver without reaching behind Gordon.
We see a teletype begin to print a message headed "ATTENTION - HOMICIDE DIV. - KENPORT POLICE". A moment later, as Bannion reads it, it is headed "ATTENTION HOMICIDE DIV.... KENPORT POLICE", the hyphens removed and an ellipsis added.
When Sgt Bannion first meets Lucy Champam in 'The Retreat' bar the waiter pours Bannion a glass of beer with a head at least 2 inches thick. Bannion is then seen to sip from the glass and the beer has virtually no head at all.
As Bannion is moving out of his house, he goes to a back room to get something. As he goes around a corner, we see his shadow stop, then it just disappears. Bannion then comes back into the shot carrying his bag. An obvious cut, but done without the camera being moved.
When Glenn Ford is conversing with the commissioner and things get heated, the commissioner asks Ford, "Just what are you inferring?". This is a common mistake, as Glenn Ford was not inferring anything; he was 'implying' - it was the commissioner who was inferring.