 Gehre, along with Bonhoeffer, was sent to the Buchenwald concentration camp.From there, he was put onto a transport of SS special detainees and on 5 April incarcerated in the Flossenbürg concentration camp.On 9 April 1945, after an SS flying court-martial, Gehre and Bonhoeffer along with Admiral Canaris, General Oster, General Sack and Captain Theodor Strünck were executed at Flossenbürg by hanging.