He took acting classes and gave his stage debut in Stendal, playing Dr. Stribel in Paul Helwig's Die Flitterwochen.

His big breakthrough was in 1966 with the three-part television show Die Gentlemen bitten zur Kasse, in which he played train robber Michael Donegan.

In 1970-71, he co-starred in three crime dramas directed by Jesus Franco, She Killed in Ecstasy, The Death Avenger of Soho [de] and The Devil Came from Akasava.

[5] When the second public television station in West Germany, the ZDF, started planning a new mystery series with a different type of investigator in 1973, he was chosen for the character of detective Stephan Derrick, with sidekick assistant Harry Klein (played by Fritz Wepper).

[citation needed] The last of 281 episodes was filmed in 1998, when Tappert reached his self-imposed age limit of 75 years old for being a television actor.

Similarly, Bavaria's interior ministry said it was considering stripping the late actor of an honorary chief police inspector title awarded to Tappert in 1980.