After the war , the PWIS became known as the War Crimes Investigation Unit ( WCIU ) , and the London Cage became the headquarters for questioning suspected war criminals . Among the Nazi war criminals confined at the London cage was Fritz Knoechlein , who was in charge of the murder of 100 British prisoners who had surrendered at Le Paradis , France in May 1940 . Knoechlein was convicted and hanged in 1949
murder of 100 British prisoners
Le Paradis massacre
Alexander Scotland