The botched execution in April of a man convicted of murder brought to the fore of national consciousness the precarious state of capital punishment. An article in Chemical & Engineering News (C&EN), the weekly news magazine of the American Chemical Society, details the history of lethal injection, what went wrong in April and how states are currently handling the practice, once deemed the most humane way to execute prisoners.

Jyllian Kemsley, a senior editor at C&EN, explains that the three-compound procedure prison officials use to carry out executions by lethal injection was first adopted in 1977 by Oklahoma, the same state where the latest botched execution took place. Under the original protocol, the first compound is supposed to make the condemned person unconscious. The second stops the person's breathing, and the third stops the heart. Although in theory physically painless other than the initial needle insertion, lethal injection has been riddled with major problems.

Compared to other current execution methods, including gassing, hanging and electrocution, lethal injection has the highest rate (7.1 percent) of complications. One of the challenges contributing to this high rate is that guidelines for administering the compounds do not allow for differences in the weight, age or physical condition of the person receiving the drugs. This could lead to prisoners remaining conscious as they receive the second two compounds, which cause suffocating and burning. Another big problem is one of supply. Drug manufacturers don't want their products used for lethal injection. States are turning to entities called "compounding pharmacies" and enacting new laws to shield these suppliers, but these are now being legally challenged.