Set in the small city of Bad Tölz in Upper Bavaria between Munich and the border to Austria, the series is about the activities of the local Kriminalpolizei as personified by Benno Berghammer (Ottfried Fischer), the eponymous Bulle (literally "bull", a German slang word for "policeman" much like "cop" in English, as well as an allusion to his bulky appearance), and Sabrina Lorenz (Katerina Jacob), two Kommissare who invariably, at the beginning of each episode, are faced with murder in the seemingly idyllic small town of Bad Tölz or its rural surroundings.
Generally, no violence is shown, and although the plot is always well constructed and the murder cases are always plausible and realistic, the huge popularity of the show is due to the underlying comedy which pervades each episode.
An only child and heavily overweight, he still lives with his widowed mother (a concept referred to as "Hotel Mum" in Germany) Theresia "Resi" Berghammer (Ruth Drexel), who is running a small bed and breakfast in Bad Tölz.
Nadine Richter, played by Katharina Abt [de; fr], replaced Sabrina Lorenz in 2006 as Benno Berghammer's police partner.
For example, double standards of morality are frequently thematized (the Catholic Church doing business with shady land developers and thus potentially harming the environment; members of the clergy associating with prostitutes; Bavaria's political élite—invariably CSU— hypocritically claiming they only want what is best for the citizens; etc.).