Mäurer studied law at the University in Marburg and Bremen and reached his degree in 1978.

In 1970 Mäurer became a member of German Social Democratic Party (SPD).

In 2008 he followed Willi Lemke as Minister for Interior and Sport (Senat Böhrnsen II).

The office of Ministers in the Free Hanseatic Citys is called Senator.

The Miri-Clan, a large family of Lebanese origin with an estimated 2,600 members, were dominating the Mongols MC, while the Hells Angels had connections to far-right hooligans.