At the time she was abducted by Brian Nichols, she had already given up her daughter, watched her husband die and went through three unsuccessful stints at drug rehab. Nichols (played by David Oyelowo in the movie) had been dubbed the Atlanta courthouse killer after slaying four people, including the judge, while escaping custody.
"A circumstance under which a murderer takes you hostage in your own home is your worst nightmare," Oyelowo says. "Somehow it became a blessing."
Smith said that Oyelowo's performance was pitch perfect and admitted to tearing up at points during the movie.
"It's hard in a sense to go back and realize four people lost their lives," Smith told ET. "But also it's a day that changed my life for the better."
Both Smith and Nichols' lives were changed when she started reading him Rick Warren's The Purpose Driven Life - a day-by-day guide to leading a Christian life. Smith vowed to stay away from drugs and Nichols began to soften towards her.
"There is a lot of hope in [Captive]," says Kate Mara, who plays Smith in the movie. "Someone who thought her life was over for a really long time found herself again in a really intense situation."
During the hostage situation, Smith was able to get away and call 9-1-1. Nichols eventually gave himself up and was given multiple life sentences in 2008. Although Smith reportedly hasn't had contact with Nichols since his trial where she provided evidence, she seems to have forgiven him.
"[Nichols] was a sinner saved by God's grace just like I am and just like everyone else is," Smith said. "He was somebody's son. He was somebody's father."