If, like me, you’re an avid reader of depressing news stories, then you may have come across several articles this week reporting on the recent decision by the government of Papua New Guinea to legalise the death penalty.
Now I don’t want to get into a discussion on the morality of the decision itself (I have neither the word count nor the time), but it did get me thinking about the science of executions. Although it may sound obvious, just exactly how do the major forms of execution work, and which, if any, should be considered the most humane?…
One of the oldest forms of execution, the principle behind hanging has remained unchanged for centuries. The favoured modern variation is termed the ‘long drop’ and was the method used to kill former Iraqi dictator Saddam Hussein in 2006.
Those planning the execution calculate the so-called ‘drop distance’ required to break the neck based on the height, weight and build of the condemned. Typically their calculations aim to cause the body to move quickly enough after the trap door opens to produce between 1,000 and 1,250 foot-pounds of torque on the neck at the point the noose jerks tight.
This requires a distance of around 5 to 9 feet with the noose knot placed under the jaw at the left side of the subject’s neck. The resulting jolt severs the spinal cord leading to a rapid drop in blood pressure and a resultant loss of consciousness. Brain death then takes several minutes to occur and death is not complete until 15-20 minutes after the trap door is released, although the individual at the end of the rope is unlikely to experience any of it.
Unfortunately, history shows that hanging is relatively easy to botch, particularly if the executioners make a mistake in their calculations. A rope that is too long can result in decapitation, whilst one that is too short can cut off breathing and blood flow through the carotid arteries in the neck. In these circumstances loss of consciousness is not always as quick, and the condemned can end up struggling for nearly 30 minutes.
Traditionally associated with the execution of covert spies and enemy prisoners during the war, death by firing squad has been heavily featured in numerous period films and television shows.
However, the reality is far removed from the old cinematic cliché of a victim boldly striding to the front of a line of rifleman and rattling off a few final words. Instead, the convict is strapped to a chair with a target pinned over his heart; a black hood is optional. Five expert marksmen then take aim from a distance of no less than 25 feet and all fire at exactly the same time.
Death by firing squad has been reported to be quicker than lethal injection. In his book ‘Elephants on Acid: And Other Bizarre Experiments’, Alex Boese states that in the 1938 execution of John Deering, the prison physician monitoring the inmate’s heartbeat reported that the time between the shots and complete cessation of rhythm was a mere 15 seconds.
One of the most popular methods of execution, the general approach is to introduce a lethal chemical cocktail into the bloodstream of the condemned criminal. A barbiturate is present to bring on sedation and suppress respiration, a neuromuscular paralytic helps to halt breathing and reduce body convulsions, and a potassium electrolyte serves to stop the heart.
The system is set-up under the principle of ‘toxic-redundancy’, so that each drug in isolation is sufficient to bring on death. Bizarrely, the dosage remains constant irrespective of the criminal’s weight, height or build. As a result, scientists have recorded instances in which breathing and cardiovascular activity have been sustained following the injections.
Criminals have also been caused unnecessary suffering due to unskilled executioners mishandling jabs, missing veins and using blocked IVs. It’s a problem that is likely to persist, given that most medical codes prevent trained personnel from becoming involved in a process designed to do harm.
The worrying frequency with which issues have been recorded has led several courts and state governments in the US to place a moratorium on the practice whilst further evidence is collected.
The Electric Chair
Although it may seem counter-intuitive, the electric chair was actually conceived as a humane alternative to hanging. First used to execute axe-murderer William Kemmler in 1890, a high voltage alternating current is applied to the body of the criminal, typically starting at 2,000 volts and 5 amps with the voltage varying periodically. This causes instant contraction and rigidity of the muscles, leading to a cessation of heart and lung activity.
The practice figured prominently in a dispute between Thomas Edison and George Westinghouse regarding the relative merits of direct vs. alternating current. Edison sought to prove that the latter was too dangerous and so decided to equip the new Electric Chair at America’s ‘Sing Sing’ prison with one of the his competitor’s AC generators.
Unfortunately the inexperienced executioners drastically underestimated the amount of electricity required to effectively kill Kemmler. At first they only succeeded in burning him for 17 seconds, at the end of which he was still twitching. It took a second jolt for a further 70 seconds before he was finally pronounced dead. Westinghouse was later heard to comment, “they could have done better with an axe”.
The Gas Chamber
One of the greatest outcries over the new laws in Papua New Guinea has stemmed from the approval of suffocation, or, to give it its full title, medically induced oxygen deprivation, as a state-regulated means of execution.
The most common means of facilitating this process is through the use of a gas chamber. The inmate is sealed inside the device, either strapped to a chair or freestanding, and a heart monitor is attached.
The cyanide ions act as an irreversible enzyme inhibitor, binding to the iron atoms of cytochrome c oxidase (aa3) in the mitochondrial membrane. This causes the enzyme to denature and means the final transport of electrons from aa3 to oxygen cannot be completed, resulting in the failure of aerobic respiration.
Physical effects are coma, seizures and cardiac arrest. Death follows in a matter of minutes, and this time lag has previously proved a problem. Indeed, during the execution of rapist Jimmy Lee Gray in 1983, the subject gasped and flailed so much that the warden had to expel the witnesses from the observation room.
Whilst lethal injection is often thought of as the most humane method of execution, recent evidence is calling this assumption into question. A firing squad is certainly fast, but there is always the risk, however small, that a marksman will miss. Hanging has a similar potential for miscalculation, whilst suffocation and the electric chair can clearly cause undue suffering.
So it looks like I’m stumped. What do you think? Is the question answerable using scientific evidence, or is the whole concept of state-sponsored execution something that can only ever be judged morally and ethically?
If you want to find out more on this topic then why not take a look at Michael Portillo’s brilliant BBC documentary ‘The Science of Killing’.