Why did hymenth's father shot himself?

Helmuth was the son of one of the Nazi supporters. One day Helmuth overheard a conversation between his father and mother, where his father expressed the thought of killing his family, Helmuth included or committing suicide alone. What followed was a time out with his father where the spent the last quality time together. It was after this that Helmuth's father went on and shot himself in his office. The reason for the suicide, was because Helmth's father was afraid of the retaliation that he would face for the war crimes they committed under the Nazi rule. It was 1945 and the Germans had surrendered to the alliance.