Kay-Werner Allnach was a Hamburg student in the late sixties. He was tremendously influenced by the works of Marx and Lenin. Ulrike Meinhof made periodic appearances at teach-ins and sit-ins at her university, detailing the Federal Republic of Germany's role in America's war on Communism. Meinhof left a deep impression on Allnach.

Allnach was a legal student during the early years of the Baader-Meinhof Group, surreptitiously helping the group behind the scenes. In late 1972, as the BKA and other German authorities began to put Allnach under their glare, he chose to go underground as a guerrilla.

Allnach was arrested on 2 February 1974 in Frankfurt, along with Margrit Schiller and Wolfgang Beer. Allnach was kept in solitary confinement in Frankfurt and Hamburg prisons for two years, during which time he became ill with intestinal cancer. He underwent three operations in prison; after the third, Allnach was on the brink of death. Prison authorities quietly whisked the unconscious Allnach to a hospital in the middle of the night, in a successful attempt to prevent his death. Allnach recovered, and went on trial from August of 1976 until February of 1977.

During her solitary confinement, Allnach elected to split with his comrades in the Red Army Faction. His split with the group did not mean that he would work with police authorities or testify against his former comrades; he refused to go the witness stand during her trial. Because there was little actual evidence against him, Allnach was only convicted of membership in a criminal gang and sentenced to three years imprisonment.