For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I
Sister Helen Prejean accepts an offer to become pen pals with a Death Row inmate named Pat Sonnier. She meets him, gets to know him, becomes his spiritual advisor, and starts to understand how flawed the system is. Pat had terrible legal representation, he may not even be legally eligible for the death penalty, and he feels genuine remorse for his crimes—but nothing Prejean does can save him. She is present when he is finally electrocuted.
Act II
Prejean becomes pen pals with and spiritual advisor to another, much less sympathetic inmate name Robert Lee Willie. Robert is harder for Prejean to deal with, but over time, these two also form a close bond. Although Robert seems like a pretty bad dude, he also shows potential for growth. His legal case also had tons of issues—but nothing can save him, either. Prejean watches as he is executed.
Act III
Prejean becomes a vocal opponent of the death penalty but also, partly inspired by her friendship with the Harveys (the mother and stepfather of Robert's victim Faith Hathaway) makes greater efforts to advocate for victims' rights. Her message is that all killing is wrong, and the system should be fixed to reflect that.