Researchers have known for decades that the U.S. criminal justice system is discriminatory against Black people, but a new study revealed that the biases can persist beyond courtrooms and prisons into the execution chamber.

Reprieve, a legal action nonprofit, analyzed all recorded conducted and attempted lethal injection procedures in the last half century. They found that race significantly increases the odds of a botched execution, with Black people having 220 percent higher chances of experiencing one than white people.

“In their efforts to carry out executions at any cost, state officials have evaded oversight at every stage of the execution process and have engaged in illegal and underhanded practices which have contributed to botched executions,” researchers said.

The findings, which were published in a report released Thursday, focuses on 73 botched executions out of 1,407 total executions between 1977 and 2023 — what researchers called the modern era of capital punishment. About 8 percent of executions of Black people compared to 4 percent of white people were botched during that time frame.

Researchers found that Arkansas, Georgia and Oklahoma had the highest “observable” racial disparities when administering lethal injections. Ohio and the federal government had high rates of botched procedures and Alabama had the highest number of executions that were stopped midway. Arkansas and Oklahoma additionally had a higher rate of botched procedures of Black people, (75 percent and 83 percent, respectively) despite Black people comprising about a third of both prison populations.

Lethal injections first became legal in Oklahoma on May 11, 1977 and then a day later in Texas. They are the primary method of execution in the U.S. Most states use one drug or a cocktail of three to render prisoners unconscious, paralyze them to conceal evidence of pain and, finally, to stop their heart, researchers said. Proponents claimed it would be a quick and humane way to put people to death, but there is no evidence to support this.

According to the report, lethal injections, which prison officials usually administered without medical training, frequently result in botched executions that result in prolonged and painful deaths. Indicators of these botched executions included the person speaking and moving, visible reactions to pain, experiencing an allergic or violent reaction to the drugs or the executioner having difficulties locating veins or administering the drugs.

The new analysis refutes claims that lethal injections are quick and painless. Rather, botched procedures were found to be prolonged – some for several hours – and painful, with some people showing signs of choking, vomiting and bleeding in the execution chamber. Researchers said the painful deaths may be hidden by the process, including the use of a paralytic drug, tight straps to hold the person down, a white sheet to hide the body or the drawing of a curtain to block witnesses’ view.

Lethal injections may cause the person to feel as if they are choking or drowning in their fluids, suffocating or being buried alive, according to medical experts. In 2015, Supreme Court Justice Sonia Sotomayor called the procedure “the chemical equivalent of being burned at the stake.”

Researchers found that hasty executions of multiple people, the secrecy of methods, illicit procurement of execution drugs and the use of low-quality or untested drugs increased rates of botched and prolonged executions. Most pharmaceutical companies will not allow their drugs to be used in these procedures due to “moral” reasons, but their absence means lethal injections are not standardized.

Furthermore, states like Arkansas, Idaho and Florida, have passed laws prohibiting public disclosure of these procedures. According to the report, the number of botched executions is likely underreported.

Despite Alabama’s secrecy laws, such as not allowing witnesses and keeping information from the public, reported halted executions and private autopsies have revealed information about the state’s methods for capital punishment.

The report found that botched executions lasted a long time, with more than one-third over 45 minutes and a quarter more than an hour. The longest execution lasted more than three hours for Joe Nathan James Jr., a Black man in Alabama, in 2022.

Reprieve called for a moratorium on all lethal injection procedures at the federal and state levels and asked legislators in the 30 states that have capital punishment to repeal secrecy laws in light of the findings of massive racial disparities. It also recommended that witnesses be allowed to witness executions and for the Food and Drug Administration to regulate the drugs used to kill people. The organization commended Ohio, Arizona and Virginia for stopping these methods and conducting independent reviews.

Arizona carried out three executions by lethal injection in 2022, all of which were botched, according to the report. On Jan. 25, in Alabama, Kenneth Smith became the nation’s first known nitrogen gas execution, a method protested by anti-death penalty advocates and international leaders for being inhumane. Louisiana, Mississippi and Oklahoma have also approved the method, which involves asphyxiation from nitrogen gas administered through an airtight gas mask.