A respiratory care practitioner who nursed at a Los Angeles hospital, Efren Saldivar confessed to killing 40 to 50 patients over an eight-year period. Quickly christened an 'Angel of Death', he targeted patients who were already near death. He would kill them with lethal injections of the muscle relaxants Pavulon or succinylcholine chloride or, if they were on ventilators, he would decrease patients' oxygen intake. Statistical analysis indicates that the total number of murders committed by Saldivar could be as high as 200, but no convincing physical evidence will ever be available to confirm or refute this possibility - the bodies were cremated after death long before he owned up to his deeds on the wards.