Upon his execution, David Herman, Texas execution No. 110 and one of the cases Vollum studied, said, "[I]f my death gives you peace and closure, then this is all worthwhile."
Herman, 39 when he was executed, was convicted of the 1989 murder of a 21-year-old topless dancer.
After well wishes, Vollum's research showed references to religion, requesting forgiveness, expressing gratitude and pleading their innocence were among the more common themes among last statements.
"To see people asserting themselves in the moments before they're going to die is fascinating," said Vollum, who did not witness an execution during his research of the Huntsville death chamber. "Most people don't have the opportunity to do that, and it's an odd thing to see a lot of them trying to redeem themselves."
Twelve of the 292 cases Vollum studied explicitly referred to their desire to humanize themselves.
"You have these individuals who are defiled -- and rightfully so, they're capital murderers," said Vollum. "They're dehumanized, depicted as animals in a lot of ways. And so at the very point of their death, it's interesting to see them trying to make something out of their lives."