He grew up in Kassel, trained from 1967 to 1970 at the Schauspielschule Bochum and was then engaged in theatres in Wuppertal, Frankfurt, Bremen, and Hamburg, where he worked with Claus Peymann, Luc Bondy, and Peter Zadek.
In 1986, he starred in his first big role in a cinema production, which is Uwe Schrader's Sierra Leone [de].
At the Hamburger Kammerspiele, he starred in Kunst and Der Totmacher, and at the St.-Pauli-Theater in the Dreigroschenoper, in Sonny Boys, and in Arsen und Spitzenhäubchen.
Since 2006, Redl starred as the laconic and lonely commissioner Thorsten Krüger in the ZDF crime series Spreewaldkrimi, playing in Spreewald, where the aftermaths of which are sporadically filmed.
In 2013, he won the German Academy of Television award for best supporting actor for his role in Marie Brand und die offene Rechnung.