Editor’s Note: Each week we cross-post an excerpt from Katrina vanden Heuvel’s column at the WashingtonPost.com. Read the full text of Katrina’s column here.

At 6:23 pm last Tuesday, as many Americans sat down to eat dinner, Clayton Lockett lay down to die. More accurately, an Oklahoma prison official strapped him to a gurney, sedated him and then injected him in the groin with an untested mix of two more drugs—one to stop his breathing, the other to stop his heart.

Quickly, it became clear that the coldly clinical execution—what the head of the Oklahoma American Civil Liberties Union called “a human science experiment”—had gone horribly awry. At 6:36 pm, despite Lockett’s being pronounced unconscious, his head lifted off the bed. He began moving and mumbling. At 6:39, convulsing, he uttered the words, “Oh, man.” By the time the director of prisons announced that there had been a vein failure and issued a stay of execution, it was too late. At 7:06 pm, Lockett suffered a massive heart attack and breathed his last—forty-three excruciating minutes after the execution began.

While Lockett was undoubtedly guilty of heinously raping a young woman and shooting and burying alive another, his state-administered death—just the latest in a horrific series of botched executions—serves as a stark reminder that the death penalty has been a moral, economic and practical failure. According to a new study, one in every twenty-five people sentenced to death between 1973 and 2004—around 300 people—was likely innocent. Many of these wrongful convictions stem from a well-documented racial bias in the criminal justice system—55 percent of death row inmates are black or Hispanic, and those who kill whites are far more likely to receive the death penalty than killers whose victims are black. Keeping the country’s 3,000-plus inmates on death row costs us billions—California alone spends $184 million annually on capital punishment—all for a system that experts agree has never been proven to be a successful deterrent.

Editor’s Note: Each week we cross-post an excerpt from Katrina vanden Heuvel’s column at the WashingtonPost.com. Read the full text of Katrina’s column here.