In February 1943 , after being arrested , tortured and subsequently released by the Milice , the Vichy French paramilitary militia , he joined a commando group in Grenoble , assisting the OSS , and then the U.S. Army Counter Intelligence Corps . When Dachau was liberated on April 29 , 1945 , Thomas learned the whereabouts of Emil Mahl ( the " hangman of Dachau " ) , whom Thomas arrested two days later . Thomas , along with CIC colleague Ted Kraus , subsequently captured SS Major Gustav Knittel ( wanted for his role in the Malmedy massacre ) . Thomas also engineered a post-war undercover sting operation that resulted in the arrest of several former SS officers . A 1950 '' Los Angeles Daily News '' article credits Thomas with the capture of 2,500 Nazi war criminals . In the final week of World War II , Thomas also played a part in the recovery of a cache of Nazi documents that had been shipped by the Nazi leadership to be pulped at a paper mill in Freimann , Germany . These included the worldwide membership card file of more than ten million members of the Nazi party . After the end of the war , Thomas learned that his parents and most of his extended family had died in Auschwitz
Malmedy massacre
Malmedy massacre
Michel Thomas