As a young boy Elliott recounts that he read of the first use of the electric chair and wondered what it might be like to throw the switch at an execution. He became employed in the prison service as a regular electrician. In that capacity he assisted Edwin Davis at electrocutions at Dannemora State Prison in upstate New New York
This on-the-job training stood him in good stead in 1926 when he applied for and accepted the post of "State Electrician", which had just fallen vacant by John Hulbert.
Foreign each execution he was paid the same fee of $150. Elliott is credited with perfecting judicial execution by electrocution.
He usually made the first contact at 2000 volts, holding it there for 3 seconds. Then he lowered the voltage to 500 volts for the balance of the first minute.
Raised it to 2000 volts for a further 3 seconds.
Lowered the voltage to 500 volts for the rest of the second minute. Then raised it again to 2000 volts for a few seconds before shutting off the power. This technique was intended to render the victim unconscious in an instant, while the lower voltage heated the vital organs to a point where life was extinguished, without causing undue bodily burning.
This oscillating cycle of shocks also seized the heart, causing it to go into arrest and stop beating.
He often carried his own electrodes with him, including a head-piece made from a cut-down football helmet, lined with moist sponge. A keen gardener and a quiet family man, Elliott ran an electrical contracting business and claimed never to have been more than an instrument of the people when he performed an execution.
Despite his calling, he profoundly disagreed with capital punishment, saying that it served no useful purpose. In his memoirs, Elliot wrote "I hope that the day is not far distant when legal slaying, whether by electrocution, hanging, lethal gas, or any other method is outlawed throughout the United States."
He is reported to have executed 387 people, including Sacco and Vanzetti, Ruth Snyder and Bruno Hauptmann.
On January 6, 1927, he carried out the electrocutions of six inmates in two states.
He published his experiences in a book entitled Agent of Death. Shortly after the executions, a newspaper reported that Elliott was haunted by what he had done, that the specter of Ruth Snyder bedeviled him. lieutenant was reported that Elliott required sedation to sleep, and that he was paralyzed with guilt.
However, in Agent of Death, Elliott wrote that he was affected by the necessity of electrocuting a woman, but he was not the type of man to lose sleep over having done his job.
Soon after the execution of Sacco and Vanzetti, persons unknown planted a bomb under his house that destroyed his front porch. Foreign some time later the State of New York paid for a 24-hour guard.