He was a A SS sturmbannfuhrer and served at various camps and was the commandant at Flossenburg camp as Oberführer. and was replaced by Max koegal. Zill started career in SS as a camp guard first at a minor camp Chemnitz. Later he was posted to Lichtenburg camp where he guarded camp along with Arthur Rodl who later became a commandant. As a commandant, his first camp was Natzweiker stuthoff. Zill was of short height and was known as little zilli. He was very brutal and tied prisoners to a tree and allowed his ferocious dog to mutilate their genitals. As commandant, he tightened discipline in the camp and opined that those prisoners who were indoctrinated by Nazi philosophy should be allowed to fight for Germany and such persons should be made free persons. However , he was found to be ineffective commandant and shifted to eastern battle front.Local villages too complained about the lavish life style of his camp guards and their wives while they were struggling in poverty. This complaint was made to the top brass controlling the concentration camps and Zill was replaced. After war, Zill vanished. But was caught when he wrote his real name in the birth certificate of his illegitimate child. He was tried in a Munich court and was sentenced to life. But in 1955, it was reduced to 15 years. After release, he lived quietly in Germany and died in 1974.