Elmo Patrick Sonnier illness, at Louisiana State Prison . He is buried in the prison cemetery. Sister Helen Prejean published a book, "Dead Man Walking" (1993), about her relationship with Elmo Sonnier and Robert Lee Willie, another inmate on Death Row whom she counseled. The book was adapted as a 1995 film of the same name directed by Tim Robbins and starring Susan Sarandon as Sister Prejean and Sean Penn as Matthew Poncelett, an amalgam of Sonnier and Willie. Her book was also adapted as an opera of the same name, first produced in 2000 by the San Francisco Opera. Elmo Patrick Sonnier
Helen Prejean experiences with Sonnier and with the convict Robert Lee Willie. He had been sentenced to death after being convicted of kidnapping, murder in two attacks in May 1980. Sister Prejean also explored the effects of maintaining the death penalty on attorneys, prison guards, other prison officials, and the families of both convicted murderers and their victims. Prejean has worked with other men sentenced to death since then. In December 2010, Prejean donated all of her archival papers to DePaul University. In 1999, Prejean formed Moratorium 2000, a petition drive that eventually grew into a national education campaign, The Moratorium Campaign,