I, Robot (2004)
Spooner gives chase and when he arrives in the lobby below - we see Spooner holding the large gun and subsequently holstering it back in his shoulder holster before picking up the gun Sunny had dropped while fleeing - which is also a large gun.
Errors in geography
The closest suspension bridges of any consequence to Chicago are several bridges over the Mississippi River (200 miles west of the city) or the Ambassador Bridge in Detroit, Michigan , more 200 miles to the east.
Incorrectly regarded as goofs
However, we do not see the array of robots until after Spooner and Calvin arrive, so it is possible that one or more robots had to move, but this was not shown on screen.
For some reason Spooner, despite being called a liar and considered to be mentally ill, never chooses to video these events as proof that they are indeed occurring,