Born in Hagen, Westphalia, Reinecker began to write short stories already as a high school student.
In 1943, he joined the Nazi Party and worked as the editor-in-chief of a book entitled Der Pimpf about the training system of the Hitler Youth.
In the late 1960s, Reinecker and producer Helmut Ringelmann wanted to create a truly German police detective.
At first tentatively conceived as a "German Maigret", Reinecker's Kommissar Keller soon metamorphosed into a full-fledged character.
Erik Ode was chosen to play Keller in the TV series, Der Kommissar, which was finally launched in 1969 and which became a huge success.