The quote noted below pops up in the iconic introduction to the 1951–59 original "Dragnet" series. After the announcer assures everyone that the story they're about to see is totally true, Joe Friday (Jack Webb) comes on the scene. He begins by setting the scene—"This is the city: Los Angeles, California. I work here." Then he tells us exactly who he is and what the facts are involved in the current case.

In each episode, Joe Friday had several bits of consistent dialogue that remained throughout the run of the series. With the opening narration, the following ("This is the city, Los Angeles, California, I work here.") was always used. Jack Webb as an actor and producer of "Dragnet" aimed for total realism (in words and deeds) and unpretentious acting. In the end, the main goals which Webb always sought were clearly achieved according to TV media critics of the 1950s and 60s .

More Info: en.wikipedia.org