Christie's crimes were committed during the 1940s and early 1950s. During this time, he was employed as a medical officer at the Broadmoor Hospital for the Criminally Insane, where he was able to access drugs and poisons. He also had access to a car, which he used to dispose of the bodies of his victims.
The Sinister Secrets of John Christie: Unraveling the English Serial Killer's Enigma