Lethal Injection in the USA

Lethal injection is virtually the universal method of judicial execution in the United States.

Table of Contents

Of the 1,607 executions carried out in the USA up to the end of 2024, 1,419 have been by lethal injection, including those of 12 women.

Execution Statistics by State

A comprehensive state-by-state record of executions by lethal injection:

State	First Used	1982–1999	2000–2025	State	First Used	1982–1999	2000–2025
Alabama	12/02/2002	0	51	Mississippi	07/17/2002	0	19
Arizona	03/03/1993	17	22	Montana	05/10/1995	2	1
Arkansas	06/25/1990	20	10	Nebraska	08/14/2018	0	1
California	02/23/1996	5	6	Nevada	12/06/1985	7	4
Colorado	10/13/1997	1	0	New Mexico	11/06/2001	0	1
Connecticut	05/13/2005	0	1	North Carolina	03/16/1984	13	28
Delaware	03/14/1992	9	6	Ohio	02/19/1999	1	55
Federal*	06/11/2001	0	15	Oklahoma	09/10/1990	19	108
Florida	02/23/2000	0	65	Oregon	09/06/1996	2	0
Georgia	10/25/2001	0	54	Pennsylvania	05/02/1995	3	0
Idaho	01/06/1994	1	2	South Carolina	05/31/1996	19	20
Illinois	09/12/1990	12	0	South Dakota	07/11/2007	0	5
Indiana	07/18/1996	4	14	Tennessee	04/19/2000	0	7
Kentucky	05/25/1999	1	1	Texas	12/07/1982	199	394
Louisiana	03/05/1993	5	3	Utah	08/28/1987	4	1
Maryland	05/16/1994	3	2	Virginia	01/24/1995	48	34
Missouri	01/06/1989	41	59	Washington	10/13/1998	1	2
Wyoming	01/22/1992	1	0

*Carried out at the United States Penitentiary, Terre Haute, Indiana.
Total Executions by Lethal Injection (to March 20, 2025): 1,426.

Historical Background

Lethal injection was first considered as a judicial execution method in the United States in 1888 when New York physician J. Mount Bleyer, M.D., proposed it in the Medico-Legal Journal.

Dr. Bleyer argued that intravenous injection would be cheaper, more humane, and would strip condemned felons of the public “hero status” frequently associated with public hangings.

He proposed the intravenous administration of six grains of morphine.

However, the proposal was not adopted at that time; New York chose instead to invent and introduce the electric chair.

Development of the Modern Protocol

With the reinstatement of the death penalty following the U.S. Supreme Court’s ruling in Gregg v. Georgia (1976), the State of Oklahoma sought a cost-effective method to replace its derelict electric chair.

In 1977, Oklahoma State Chief Medical Examiner A. Jay Chapman drafted the world’s first sequential three-drug lethal injection protocol.

The protocol was reviewed and endorsed by Dr. Stanley Deutsch, Chairman of the Department of Anesthesiology at the University of Oklahoma College of Medicine, and passed into law by the Oklahoma Legislature that same year.

Dr. Deutsch described administering drugs through an intravenous drip to produce rapid, painless unconsciousness followed by death:

“Having been anaesthetised on several occasions with ultra short-acting barbiturates and having administered these drugs for approximately 20 years, I can assure you that this is a rapid, pleasant way of producing unconsciousness.”

Although Oklahoma was the first state to legislate the protocol, Texas enacted matching statutory provisions later in 1977 and carried out the world’s first lethal injection on December 7, 1982.

Charles Brooks Jr. was executed at the Huntsville “Walls” Unit for the 1976 murder of David Gregory.

The execution proceeded smoothly; Brooks’ girlfriend, Vanessa Sapp, witnessed the procedure. The infusion began at 12:07 a.m., and Brooks was pronounced dead at 12:16 a.m.

By the end of 2010, Texas alone had executed 463 inmates by lethal injection.

States Using Lethal Injection

As of January 1, 2020, twenty-nine states retained statutory lethal injection protocols, either as their exclusive method or as an option alongside alternative execution methods:

Alabama, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Idaho, Indiana, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, and Wyoming.

Only 32 states had actually carried out executions by injection up to the end of 2010.

Although Connecticut and New Mexico subsequently abolished the death penalty, inmates initially remained under capital sentences during legislative transitions. The governors of Colorado, Oregon, and Washington subsequently imposed executive moratoria on executions.

States progressively adopted injection to phase out older apparatuses:

Florida introduced lethal injection as an alternative to the electric chair in 1999 following botched electrocutions;
Alabama added lethal injection on July 1, 2002;
Nebraska replaced electrocution with lethal injection in 2009 after its Supreme Court ruled the electric chair unconstitutional.

Many states retrofitted existing execution chambers to avoid capital expense.

California constructed a new lethal injection suite at San Quentin State Prison in 2009 at a cost of $853,000, though it remained unused due to federal court moratoria.

At Washington State Penitentiary in Walla Walla, lethal injections were administered in the chamber directly beneath the historic gallows trapdoors.

In Utah, the same execution chamber is equipped to conduct both firing squad executions and lethal injections.

U.S. Federal and Military Executions

Federal Facility at Terre Haute

The U.S. Federal Bureau of Prisons constructed a dedicated $300,000 lethal injection facility at the United States Penitentiary in Terre Haute, Indiana.

Housed in a separate brick building outside the main prison perimeter, the death house features five observation rooms surrounding the central execution chamber.

The chamber resembles a modern hospital surgical suite, lined with clinical green tiles, a sink, and a central padded gurney fitted with five broad Velcro restraint straps.

Intravenous infusion lines pass through a small opening in the masonry wall connecting to the executioner’s preparation room.

Only the executioner’s room is fitted with one-way mirrored glass; the remaining witness rooms have two-way glass with drawn privacy curtains.

A dedicated telephone line connects the chamber directly to the Department of Justice in Washington, D.C., where the President holds sole authority to grant an executive stay or clemency.

A ceiling-mounted video camera transmits real-time footage to the executioner’s station to monitor the inmate for signs of physical distress.

Notable Federal Executions

Timothy McVeigh: Executed on June 11, 2001, for the Oklahoma City bombing, which killed 168 people. Intravenous lines delivered the chemical sequence through a catheter inserted into McVeigh’s right leg. Infusion of the first drug began at 8:10 a.m., the second at 8:11 a.m., the third at 8:13 a.m., and he was pronounced dead at 8:14 a.m.
Juan Raul Garza: Executed on June 19, 2001, on the same gurney for drug trafficking and three murders.
Louis Jones Jr.: Executed on March 18, 2003, for kidnapping, rape, and murder.

Following a seventeen-year hiatus, federal executions resumed in July 2020 under an updated single-drug pentobarbital protocol, executing three condemned men in a single week:

Daniel Lewis Lee: Executed July 14, 2020;
Wesley Ira Purkey: Executed July 16, 2020;
Dustin Lee Honken: Executed July 17, 2020.

All three executions proceeded without mechanical complications. An additional ten federal executions were carried out between August 2020 and January 2021.

Military Executions

The United States Armed Forces transitioned from military hanging to lethal injection under Department of Defense directives.

The military execution facility is located in the basement of the Disciplinary Barracks at Fort Leavenworth, Kansas.

Procedural Administration and Drug Quantities

Lethal injection procedures follow standardized institutional steps, though operational details vary between jurisdictions.

The prisoner is secured to a wheeled gurney or fixed surgical table using leather or nylon straps across the legs, thighs, waist, chest, and wrists.

The arms are extended outward on padded lateral arm boards.

Phlebotomists or trained execution technicians insert a 14-gauge catheter—the largest gauge standard intravenous needle—into accessible peripheral veins in each arm (one acting as the primary infusion line and the other as a reserve line).

Once vein access is secured, the lines are flushed with 10cc of heparinized saline solution to prevent catheter clotting, and a continuous 1,000cc intravenous drip of 0.9% normal saline is established.

The prisoner is wheeled into the execution suite, or the partition curtains are retracted to allow official, media, and family witnesses to observe.

The Classic Three-Drug Protocol

Upon receiving the warden’s signal following the condemned’s final statement, executioners deliver three chemicals manually via syringes through extended intravenous tubing:

Sodium Thiopental ($C_{11}H_{17}N_2NaO_2S$): 2 to 3 grams dissolved in 80cc of sterile water. An ultra-short-acting barbiturate anaesthetic delivered at eight to ten times normal clinical dosage, designed to induce deep surgical anaesthesia within 10 to 20 seconds.
Pancuronium Bromide (Pavulon, $C_{35}H_{60}N_2O_4$): 50 to 100 milligrams. A non-depolarizing neuromuscular blocking agent that competitively blocks acetylcholine receptors at the motor endplate, completely paralyzing the voluntary skeletal muscles, collapsing the diaphragm, and arresting respiration.
Potassium Chloride ($KCl$): 100 milliequivalents (mEq) in 50cc of aqueous solution. A high-concentration electrolyte solution that depolarizes cardiac muscle cell membranes, extinguishing the electrical cardiac conduction system and inducing sudden cardiac arrest in diastole.

Each chemical is followed by an intervening flush of saline solution to clear the tubing and prevent chemical precipitation that could occlude the catheter. The complete chemical delivery takes between three and five minutes.

Texas Drug Quantities

Texas utilized the classic three-drug sequence in the following measured volumes:

120cc of aqueous solution containing 3.0 grams of sodium thiopental;
50cc of solution containing 100 milligrams of pancuronium bromide;
70cc of solution containing 140 mEq of potassium chloride.

Medical Controversies and Legal Challenges

All pharmaceutical agents used in lethal injection were developed for standard therapeutic medicine.

Sodium thiopental induces rapid unconsciousness when injected intravenously, but redistributes rapidly into peripheral body fat stores, causing plasma drug concentrations to fall.

In April 2005, British medical journal The Lancet (Vol. 365, Issue 9468) published a study analyzing post-mortem blood toxicology from 49 executed inmates in North Carolina and South Carolina.

The authors asserted that 21 of the executed inmates exhibited post-mortem thiopental blood concentrations lower than those required for surgical anaesthesia, suggesting that some prisoners may have experienced the suffocating effects of pancuronium bromide and the burning pain of potassium chloride while conscious.

However, forensic pharmacologists noted that sodium thiopental undergoes rapid post-mortem redistribution into adipose tissue, meaning post-mortem blood samples taken hours after death underestimate the active drug concentration present in the brain at the moment of cardiac arrest.

This was confirmed during the May 2005 execution of Michael Ross in Connecticut:

A femoral blood sample obtained 25 minutes after death revealed a thiopental concentration of 29.6 mg/L (well above surgical anaesthetic thresholds);
A second sample obtained five hours later had declined to 9.4 mg/L.

Following execution, the inmate’s face and nail beds frequently display a cyanotic, bluish tint—a standard physiological result of chemical respiratory arrest as oxygen saturation falls.

Baze v. Rees (2008) and Supreme Court Precedent

In 2007, Kentucky death row inmates Ralph Baze and Thomas Bowling challenged the constitutionality of the three-drug protocol under the Eighth Amendment’s prohibition against cruel and unusual punishment, arguing that improper administration of the anaesthetic created an unacceptable risk of severe pain.

The litigation triggered a nationwide de facto moratorium on executions while the Supreme Court considered the case.

On April 16, 2008, the Supreme Court ruled 7–2 in Baze v. Rees (553 U.S. 35) that Kentucky’s three-drug protocol did not violate the Eighth Amendment.

The Court held that to prevail, a death row inmate must demonstrate that a state’s execution protocol creates a “substantial risk of serious harm” and that a feasible, readily available alternative exists that significantly reduces that risk.

Executions resumed across the United States immediately following the decision.

Automated Execution Machines and Multiple Executions

While most states rely on executioners manually depressing syringe plungers from behind a partition, several jurisdictions experimented with automated equipment.

The mechanical execution machine, developed by computer engineer Fred Leuchter, utilized electronically controlled motorized syringe drivers programmed to inject the chemical sequence and intervening flushes at preset intervals when triggered by prison staff depressing simultaneous switches.

Automated syringe drivers were utilized in Missouri, Illinois, and North Carolina before states abandoned them due to mechanical jamming risks and legal challenges regarding compounding verification.

Multiple Same-Day Executions

States with large death row populations occasionally conducted multiple executions on a single day:

Arkansas (1994 & 1997): Arkansas executed three men on August 3, 1994, and carried out a double execution on January 8, 1997;
Texas (1997 & 2000): Texas carried out two executions on December 9, 1997, and repeated double executions in 2000.

During multiple executions, the chamber was cleared, the deceased inmate removed, the table sanitized, and fresh intravenous lines and restraint straps prepared for the subsequent prisoner.

Ohio’s Protocols and the Romell Broom Case

On September 15, 2009, Ohio attempted to execute fifty-three-year-old Romell Broom at the Southern Ohio Correctional Facility in Lucasville for the 1984 rape and murder of Tryna Middleton.

Execution technicians spent over two hours attempting to secure an intravenous line, sticking Broom eighteen times across his arms, wrists, and ankles without success, puncturing muscle tissue and causing severe pain.

Governor Ted Strickland issued an emergency one-week reprieve, halting the execution. Broom was returned to death row, becoming only the second man in modern American history to survive an execution attempt (Broom died on death row from COVID-19 in December 2020 before a second execution could be scheduled).

Following the Broom disaster, Ohio overhauled its execution procedures:

Single-Drug Protocol: Ohio became the first state to abandon the three-drug sequence, adopting a single lethal overdose of 5 grams of sodium thiopental;
Intramuscular Backup: The state established an emergency secondary protocol permitting the intramuscular injection of hydromorphone (an opioid narcotic) and midazolam into the prisoner’s muscle tissue if intravenous access proved impossible.

Pharmaceutical Shortages and Protocol Changes (2010–2025)

Beginning in 2010, European pharmaceutical manufacturers and the European Union instituted export bans on medical anaesthetics intended for use in American capital executions.

In 2011, Hospira—the sole American manufacturer of sodium thiopental—ceased production after Italian authorities demanded guarantees that the drug would not be used in executions.

Deprived of sodium thiopental, states revised their execution statutes, testing alternative pharmaceuticals:

1. Pentobarbital Sodium Overdoses

In December 2010, Oklahoma became the first state to use pentobarbital sodium (Nembutal)—a barbiturate commonly used in veterinary euthanasia and medical surgery—as the first-stage sedative in its three-drug protocol.

In 2012, Texas transitioned from the three-drug method to a single massive overdose of 5 grams of compounded pentobarbital.

The single-drug pentobarbital protocol became the preferred method for the Federal Bureau of Prisons and states including Georgia, Missouri, and South Dakota.

2. The Midazolam Protocol and Botched Executions

When manufacturers of pentobarbital restricted distribution, several states turned to midazolam hydrochloride, a benzodiazepine sedative:

Florida (2013): Became the first state to deploy midazolam as the first chemical in a three-drug cocktail;
Dennis McGuire (Ohio, January 16, 2014): Ohio executed McGuire using an untried combination of intravenous midazolam and hydromorphone. McGuire gasped, choked, and struggled on the gurney for over twenty-five minutes before dying;
Clayton Lockett (Oklahoma, April 29, 2014): Oklahoma administered a three-drug protocol utilizing midazolam. The intravenous line in Lockett’s femoral vein ruptured into the surrounding groin tissue. Lockett writhed, clenched his teeth, and attempted to rise from the gurney. The execution was halted, and Lockett died 43 minutes later from cardiac arrest inside the chamber;
Joseph Wood (Arizona, July 23, 2014): Arizona injected Wood with fifteen sequential doses of midazolam and hydromorphone over two hours, during which Wood gasped and snorted over 600 times before expiring.

Despite these cases, the U.S. Supreme Court upheld the constitutional validity of midazolam in Glossip v. Gross (2015).

3. Novel Formulations: Etomidate and Fentanyl Citrate

Florida (August 24, 2017): Became the first state to use etomidate—a non-barbiturate intravenous anaesthetic—executing Mark Asay;
Nebraska (August 14, 2018): Became the first state to execute an inmate using fentanyl citrate (a synthetic opioid) in a four-drug protocol comprising diazepam, fentanyl citrate, cisatracurium besylate, and potassium chloride, putting Carey Dean Moore to death.

Lethal Injection in International Jurisdictions

Beyond the United States, several nations adopted lethal injection:

China: Introduced execution vans and chamber-based lethal injections alongside shooting in 1997, utilizing mobile execution chambers fitted with automated syringe drivers;
Thailand: Replaced execution by machine-gun shooting with lethal injection in October 2003;
Vietnam: Replaced military firing squads with lethal injection in 2011, though executions stalled for years due to EU export restrictions on lethal chemicals;
The Philippines: Adopted lethal injection in 1996, executing seven men before abolishing capital punishment in 2006;
Guatemala: Introduced lethal injection in 1996, carrying out five executions (including the broadcast execution of Manuel Martínez Coronado in 1998) before eliminating the death penalty for civil offences.

Frequently Asked Questions

What was the original three-drug lethal injection protocol?

Developed in Oklahoma in 1977, the classic three-drug protocol consisted of sodium thiopental (to induce deep surgical anaesthesia), pancuronium bromide (to paralyze all voluntary muscles and stop breathing), and potassium chloride (to stop the heart through cardiac arrest).

Why did American states abandon sodium thiopental?

In 2010 and 2011, European pharmaceutical suppliers and the European Union instituted strict export bans prohibiting the sale of medicinal anaesthetics for capital executions, while domestic manufacturers ceased production, forcing states to seek alternative sedatives.

What is the single-drug pentobarbital protocol?

Under the single-drug protocol pioneered by Ohio and Texas, prison authorities administer a single massive overdose (typically 5 grams) of pentobarbital sodium. The barbiturate depresses the central nervous system, causing respiratory and cardiac arrest without requiring a secondary paralytic or potassium chloride.

What happened during the execution of Romell Broom in Ohio?

On September 15, 2009, executioners spent over two hours attempting to establish an intravenous line on Romell Broom, sticking him eighteen times across his limbs. Unable to access a usable vein, Governor Ted Strickland granted an emergency stay, halting the execution.

What did the Supreme Court decide in Baze v. Rees (2008)?

The Supreme Court ruled 7–2 that Kentucky’s three-drug lethal injection protocol did not violate the Eighth Amendment’s ban on cruel and unusual punishment, holding that inmates must prove a protocol presents a substantial risk of serious harm compared to feasible, readily available alternatives.

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