It was the late 70s, and Kathleen Dennehy was working at Massachusetts Correctional Institution at Concord, the oldest running men's prison in the state. Opened in 1878, it has a vault filled with corrections records dating back to the turn of the century, both from the now-demolished state prison that preceded it and from MCI-Concord's prison cemetery. The weathered papers include death certificates, sentencing documents, and other records, including those of Sacco and Vanzetti, the famous 20s anarchists ostensibly sentenced to death for first-degree murder, but whose larger crime was being Italian.

But one particular document—from the early 1900s, she estimates—caught her eye. "The wording was so unusual," says Dennehy, who now works for the National Council on Crime & Delinquency. "It was for a prisoner who had died in custody at the old state prison, and next to 'cause of death', it read 'judicial homicide.'"

It's a telling turn of phrase. Sometime during the 20th century—historical sources disagree as to the exact year—the term "capital punishment" entered American legal parlance, and with it a sanitized rebranding of state-sanctioned killings. Dennehy had never heard the term "judicial homicide" used before encountering it in the vault, nor—during her 30-year career in corrections that followed—did she hear it used again. Taken separately, the words "capital" and "punishment" are both qualifiers for the condemned, but "judicial homicide" points to someone else entirely. It's the guard standing at the door to the death chamber, the strap-down team member holding the prisoner's ankles, and the physician inserting the needle. It's the people who walk into the death chamber and walk back out, and sure, their task is judicial. But just because we call it "punishment" now, does it affect their psyches any less than when we called it "homicide"?

Unlike other professions that involve death, such as the police force or the military, few corrections officers enter the field with the expectation that they'll eventually have to kill somebody.  On the contrary, many view themselves as protectors.

"We are caretakers for a population of people who instantly go out of sight, out of mind for the general public," says Jennie Lancaster, a retired prison warden with the North Carolina Department of Corrections. In 1984, she oversaw the execution of Velma Barfield, the first woman in 35 years to be executed in the United States and the first to die of lethal injection.

"At job interviews we don't ask things like, 'So how do you feel about wheeling away a body?'" Lancaster says. "But maybe we should. It's not a role many of us picture ourselves playing."

And why would they? When it comes to the death penalty, much media attention has been paid to families of the victims and the condemned. Not so with corrections officers. It takes stories of executions gone wrong, such as Clayton Lockett's heart attack after a failed lethal injection in Oklahoma last April, or Joseph R. Wood III's injection of 15 times greater than the standard dosage, to shift the lens. Then, we wonder: What must it have been like to be in that room? To watch a person's body convulse, rather than calmly shut down? What is it like to wait two hours and 600 gasps of air for a man to die?

Following the media circus around Velma Barfield's execution, Lancaster was asked to appear on The Oprah Winfrey Show for a panel on capital punishment in 1988. This was the same year that Congress reinstated the federal death penalty, with then-president Reagan as a vocal supporter (though it should be noted that the Supreme Court put capital punishment back into effect several years earlier in 1976, after a four-year moratorium). On the episode, Lancaster coined the phrase "silent actors" to describe the corrections officers who have to physically mete out executions, and whose names are protected from the press.

"There is a code of silence around execution teams, and it's used to protect people who are involved in them," says Lancaster, who was one of the first wardens to bring public awareness to corrections job stress. Still, she acknowledges that the flip side of protection is isolation, and that execution teams have few people to talk about their experiences with.  "It's not necessarily something you go and bring up in church," she sighs with a North Carolinian drawl.

So how do you cope with that kind of job stress? In the American legal system, we burden a small handful of people with what is arguably the hardest part of corrections: There are only 38 execution chambers in the country, five of which—in New Hampshire, Kansas, Nebraska, California, and New York—are never used. When almost nobody can relate to your job, is it easier to quell your feelings about executions than express them?

A 2005 study published in Law and Human Behavior titled "The Role of Moral Disengagement in the Execution Process" sought to answer that question. Conducted by then-Stanford psychology student Michael Osofsky, social cognitive theory pioneer Albert Bandura, and Stanford prison experimenter/psychologist Philip Zimbardo, the five-year study aimed to pinpoint the psychological strategies officers use to repeatedly perform, and cope with, executions.

"The core thesis is that individuals must morally disengage in order to perform actions and behaviors that run opposite and are counter to individual values and personal moral standards," Osofsky says. "Capital punishment is a real-world example of this type of moral dilemma where everyday people are forced to perform a legal and state-sanctioned action of ending the life of another human being, which poses an inherent moral conflict to human values."

To develop his moral disengagement metric, Osofsky studied eight behaviors: moral justification, the use of euphemistic language, advantageous comparison (for example, "the execution prevented him from killing many more people"), displacement of responsibility, diffusion of responsibility, distortion of consequences (i.e. minimizing the execution process: "lethal injection is humane as the inmate has no pain"), attribution of blame, and dehumanization of the prisoner. During his interviews with execution teams and uninvolved correctional officers, he used the Clinician-Administered PTSD Scale (CAPS-1) Life Events Checklist and the Beck Depression Inventory, two tools psychologists use to measure trauma and depression.