Karl-Eduard attended a boarding school at Bad Godesberg and joined the Sozialistische Arbeiter-Jugend youth organisation of the Social Democratic Party of Germany in 1932.

After his capture, he began to work for the British Ministry of Information and for the German-language service of the BBC, where his talents as a broadcaster were soon recognised.

His political bias soon became apparent to his superiors and he was removed from his position in Cologne and returned to the NWDR's Hamburg offices until his eventual dismissal in 1947, after being accused of spreading communist propaganda.

As host of Der Schwarze Kanal, which ran for 20 minutes every Monday night, Schnitzler edited together extracts of Western television footage and recorded caustic, virulently anti-Western commentary over it.

In Schnitzler's late career, he published several articles in the satirical magazine Titanic and continued to work with the small German Communist Party.

In 1998, Schnitzler appeared on the local German television talk show Ich stelle mich (TV Berlin).