Click here for a special offer. Click here for our free newsletter. Some 31 state legislatures, most since the mid-1980s, have permitted concealed weapons if owners pass a background check and safety course. Missouri will be the nation's first referendum on the issue.
Proponents believe criminals are deterred by fear potential victims are armed.
Critics say the laws make public places more dangerous. A Kansas City Star poll shows the vote too close to call. If the measure wins, neighboring Kansas may follow suit. Reporters, photographers, and film crews say observing raids and searches enables accurate portrayals, but some journalists fear that their presence prompts officers to change their behavior for public consumption. New Los Angeles rules bar journalists from accompanying officers on searches of private property.