Josef Jakobs SW3, on 4–5 August 1941. The trial was held "in camera" because the German agent had been apprehended in a highly classified intelligence operation known as the Double Cross System. The British were aware that Jakobs was coming because his arrival information had been passed on to MI5 by the Welsh nationalist and "Abwehr" double agent Arthur Owens. After a two-day trial which involved hearing the testimony of eight witnesses, Jakobs was found guilty of spying and sentenced to death. Jakobs's execution took place at the miniature rifle range in the grounds of the Tower of London on 15 August
RAF Upwood farmers after he had parachuted into the area, breaking a leg in the process. He was discovered to have maps of the RAF Upwood area, a code device and almost £500 cash in his possession. Jakobs was sent to London where, after a preliminary interrogation by MI5, he spent several months at Dulwich Hospital. Jakobs was transferred to Camp 020 in April 1941 where he was interrogated by agents of MI5. On August 4 and 5, Jakobs was tried by court-martial at the Duke of York's Headquarters where he was found guilty of treachery. Jakobs was executed by firing squad