Techow was a member of the Berlin chapter of Organisation Consul and conspired to kill Rathenau with Hermann Fischer and Erwin Kern.
Techow was the getaway driver of the group and the only member to stand trial as Kern was killed by police and Fischer committed suicide.
Techow initially joined the Nazi Party after his release from prison in 1930 but was expelled for supporting the Stennes Revolt in 1931 and dropped into obscurity.
A story was circulated that Techow had changed his political beliefs after his release from prison, joined the French Foreign Legion in 1941 under the name of "Tessier" and later embarked on helping Jews escape from occupied France, but this was found to be false.
[1] In 1918, Techow volunteered for the Imperial German Navy towards the end of World War I, receiving his training as a midshipman at the Mürwik Naval School.
After Germany's defeat and the German Revolution of November 1918, he came into contact with counter-revolutionary forces and joined Marinebrigade Ehrhardt which participated in the Kapp Putsch.
These included Erwin Kern and Hermann Fischer, with whom he planned to assassinate Walther Rathenau, the Foreign Minister of Germany at the time.
While passing, Kern shot Rathenau with an MP 18 and Fischer threw a hand grenade into the car, before Techow quickly drove them away.
Rathenau was fervently mourned in Germany, with the news of his death leading to turmoil in the Reichstag and prompting millions of Germans to rally against terrorism.
He was expelled from the party in April 1931, and his last noted public appearance was in October 1933, when a monument for his fellow assassins Fischer and Kern was unveiled in Saaleck Castle.
He was taken as a prisoner of war while fighting against the Red Army in a suburb of Dresden, and held at the military training ground in Königsbrück.