Having already served 9 years for his involvement in the execution of US prisoners of war in the infamous Malmedy Massacre trial, Sepp Dietrich was re-arrested in Ludwigsburg in August 1956. He was charged by the Landgericht München and tried from 6 to 14 May 1957 for his role in the killing of SA leaders during the Night of the Long Knives in 1934. He was sentenced to 19 months for his part in that purge and returned to the U.S. military prison at Landsberg. He was released due to a heart condition and circulation problems in his legs on 2 February 1958.

His co-defendant, Michael Lippert, was also sentenced to 18 months for manslaughter and in Lippert's case this included for the manslaughter of Ernst Röhm.