Cain stays with the doomed in the death chamber, praying with them, holding their hands and offering what solace he can before they face the ultimate punishment.
"I'd rather it be me that cared about them and their soul rather than someone who was cold and did not," Cain tells CBS Radio News.
A toxic dose of chemicals is injected into the prisoner with the curtains drawn. When they swing open, the only one left in the chamber, for six long minutes, is Cain and the dying man.
"He'll breathe two breaths... all of them do that. And then he doesn't breathe anymore, and the cardiogram will go flat," explains Cain.
He says he tries to never forget the crimes that brought these men to their final hour at the state prison in Angola.
"I couldn't help the victim and so I always think about them, because you have to," he says.
The warden keeps pictures on his wall of the five men he has watched die and says executions are a painful but necessary part of the job.
After all, he says, "I'm the keeper of the keys."
By CBS Radio News' WENDY ZENTZ and CBSNews.com's CHRIS WEBER
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