How Does Lethal Injection Actually Work?

One of the most used capital punishments, but how does the lethal injection actually work?

The death penalty is enforced in 32 states in America, and capital offenses include things such as treason, espionage, and death resulting from aircraft hijacking. However, committing murder is by far the most common reason that people find themselves on death row. Over the years, execution methods have included everything from hanging, to firing squad, and even a gas chamber, but today all 32 states that have the death penalty use lethal injection, as it’s considered the most humane way to end a person’s life. So just how humane is it, and what happens when someone is given the life-ending jab?

United States has performed 1,297 lethal injection executions

There have been 1,472 executions in America since 1976. Of those executions, 3 were by firing squad, 3 by hanging, 11 by gas chamber, 158 by electrocution, and 1,297 by lethal injection. Lethal injection is the practice of injecting one or more drugs into a person to cause them to die immediately. It was first developed in the United States and is now a preferred method of execution in China, Thailand, Guatemala, Taiwan, the Maldives, and Vietnam. Once the person’s heart stops, death is pronounced. In most cases, this takes around seven minutes, although, if there are complications, it can sometimes take longer. So what’s actually injected into a person, to bring on cardiac arrest?

How does lethal injection work?

According to the Death Penalty Information Center in Washington D.C., the process for lethal injection in most states involves injecting three separate shots, all of which are delivered via intravenous drips. The first injection is an anesthetic called sodium thiopental, a strong barbiturate used to send a person into a deeply unconscious state, so pain cannot be felt. The drug affects a number of neurotransmitters, causing brain activity to be depressed and blocking the actions of brain receptors, therefore causing a dormant nonreactive state, typically within 30 seconds.


This anesthetic is intended to last throughout the lethal injection process, so when the following injections are administered, the person is completely unaware. The tubes used to administer the drugs are flushed clean with saline, and then the second injection, this time of pancuronium bromide, is administered. This drug acts as a neuromuscular blocker, preventing communication between the nervous system and muscles. As the person has no muscular control, a state of paralysis is reached.

The diaphragm, a muscle used to pull air into the lungs, stops working, causing breathing to cease. One last saline flush before the final injection is administered, this time, potassium chloride. This disrupts the electrical signaling of the heart, stopping it from beating and ending the person’s life. According to a 2002 study in the Journal of Forensic Science, the average time from the first injection to the heart-stopping is 8.4 minutes.

What happens when lethal injection goes wrong?

But what about rare cases where things go wrong and the process takes longer than anticipated? Though the general consensus is that lethal injection is the most painless and humane way to end a person’s life, there have been some botched attempts. We researched some cases that have made the headlines over the years.

Lethal injection failed on the first try when it came down to Charles Walker

Charles Walker Mugshot – Illinois Department of Corrections

In 1985, Charles Walker was convicted of two counts of murder and one count of armed robbery. He was a death row inmate at the Menard Correctional Center in Chester, Illinois, until September 12th, 1990, when Walker requested a last meal of pan-fried wild rabbit, with gravy made from the pan drippings, biscuits, and a dessert of blackberry pie with whipped cream. His execution was scheduled for after dinner.

But the execution was prolonged because of human error and equipment failure. According to Gary Sutterfield, an engineer who assisted with Walker’s execution, a kink in the plastic tubing going into his arm, stopped the flow of chemicals into Walker’s body. Additionally, the intravenous needle was pointing at Walker’s fingers, instead of his heart. Walker’s execution took far longer than it should have, and he suffered excruciating pain throughout.

Next, we have Joseph Cannon, who on April 23, 1998, prepared for his death in a Texas jail. Cannon was convicted of attempted rape and murder in 1977 when he was just 17. He spent more than half his life on death row before facing the needle. He made his final statement, and the execution process began, but a vein in Cannon’s arm collapsed and the needle popped out.


As the witnesses looked on, Cannon laid back and exclaimed “It’s come undone.” The curtains were then drawn for 15 minutes so the officials dealing with Cannon’s execution could fix the problem. When they eventually reopened the curtains, Cannon made a second final statement and the execution was completed.

And finally a case that hit the headlines this year, Doyle Lee Hamm who faced the death penalty at Donaldson Correctional Facility, in Bessemer, Alabama. Hamm had been at Donaldson since 1987 after a jury found him guilty of shooting and killing a motel clerk during a robbery. But Hamm had terminal cancer and a history of intravenous drug use, leaving his veins feeble and compromised. The attempted execution was halted after medical personnel was unable to find a vein, despite trying to insert needles in the groin, ankles, and lower legs for nearly 2 hours.

Dr. Mark Heath, the doctor responsible for examining Hamm, was quoted on NBC News as saying: “During this time Mr. Hamm began to hope that the doctor would succeed in obtaining IV access so that Mr. Hamm could ‘get it over with’ because he preferred to die rather than to continue to experience the ongoing severe pain.” Hamm survived to tell the tale and it’s not been confirmed whether or not, he will need to face another round of injections to end his life.


7.12% of lethal injection executions between 1890 to 2010, were botched

These are severe and unfortunate cases, and though of course, they are in the minority, things do go wrong. According to the Death Penalty Information Center, a national non-profit organization providing information and data on capital punishment, 7.12% of lethal injection executions between 1890 to 2010, were botched.

Capital punishment has always been a controversial topic and whichever execution method the state decides is most humane, it is likely there will always be the occasional problem. As we’ve learned today, the method of Lethal injection puts a person to sleep before inducing a cardiac arrest and most of the time it’s a straightforward procedure – a small pinprick, a combination of three substances…and then lights out.

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