On Dec. 17, 1944, an SS unit under his command captured an American army unit during the Battle of the Bulge. The SS unit's commander, Col.
Joachim Peiper, ordered them to be executed, and 84 men were shot to death by an SS execution squad. After the war Dietrich was tried for the crime, as he was the overall commander, and in 1946 he was sentenced to life in prison, but that sentence was later reduced to 25 years. He served almost ten years of that sentence and was paroled in 1955.