A new report has found that states made significantly more mistakes during the executions of Black people than they did with prisoners of other races.

The nonprofit Reprieve released an analysis of the more than 1,400 executions carried out or attempted in the U.S. since 1977. The study found 73 botched executions.

It found that Black people had 220% higher odds of suffering a botched lethal injection execution than white people.

It noted that in Georgia, 86% of botched lethal injection executions were of Black people despite executions of Black people accounting for just 30% of the executions.

The group says botched lethal injection executions occurred whether a one-drug or a three-drug protocol was used and over a third lasted over 45 minutes. A quarter of them lasted an hour or more. 

A specific case outlined in the study was the Oklahoma 2014 execution of 38-year-old Clayton Lockett.

The report found that over the course of 51 minutes, the execution team punctured Locket 16 times in an attempt to insert IV lines.

After being administered the lethal injection He "started breathing heavily, writhing, clenching his teeth and straining to lift his head off the pillow."

The team lifted a sheet and discovered that a vein had "exploded" or "collapsed" and "the drugs were not getting into the system like they were supposed to."

Lockett died of a heart attack 43 minutes after the start of his execution.

The authors say their study debunks claims that lethal injection is a quick, peaceful and painless form of execution.

The group, which is against the death penalty, called for an immediate moratorium on lethal injection executions at both the state and federal levels for further investigation.