Most common method of execution in the United States. Condemned persons are injected with three drugs:
The first drug is a tranquilizer, intended to induce unconsciousness in the condemned.
The second drug induces paralysis, rendering the condemned unable to move or breathe.
The final substance, the killing blow, is potassium chloride; a salt. The saline solution disrupts the conductive flow in the heart muscles, essentially electrically frying the heart muscle and inducing cardiac arrest, killing the condemned.
Although this method is no doubt very effective, it causes undue and excruciating pain in the condemned if the warden misses the vein and the tranquilizer fails to take hold. Supporters of the current method do not seem to realize that prisons can undertake a much easier, much less risky, and much less expensive process by simply overdosing the condemned on the first drug. No pain is felt, and the excessive dose ends the life of the condemned without suffering.
Lethal injection could be a much more humane method of execution if only the government would change the way in which it was done.