In 2012, Dateline NBC correspondent Keith Morrison nationalized the heartbreaking case of Angie Dodge, an 18-year-old woman murdered in her home in Idaho Falls, Ind. Two decades ago, police arrested an acquaintance of Dodge, 20-year-old Chris Tapp, after he confessed to participating in her murder. In the years since Tapp's conviction, hours of video documenting his interrogations with police were made public and ignited a firestorm of controversy over whether the confession that led to his life sentence for murder was false and coerced. The Idaho Falls Police Department denies the allegations and stands by Tapp's conviction. But in a surprising twist, Angie's own mother, Carol Dodge, became one of Tapp's greatest advocates and was at the helm of the fight for his exoneration as part of her ongoing mission to find the man who killed her daughter.Morrison's original reporting sparked nationwide interest in Tapp's case and inspired an outcry from advocates calling for Tapp to be freed. In March 2017, Tapp struck a deal with the state: he was released from prison immediately, but his murder conviction was upheld. Tapp remains a felon in the eyes of the law. Investigation Discovery's (ID) cameras were in the courtroom for Tapp's emotional release and now the leading true-crime network has teamed up with Morrison to share the latest installment in the Angie Dodge murder investigation, as well as Tapp's story, through an interview conducted with him three weeks after he became a free man. Produced by NBC News' Emmy Award-winning production arm Peacock Productions, the two-hour special WHO KILLED ANGIE DODGE? KEITH MORRISON INVESTIGATES premieres Memorial Day: Monday, May 29 at 8/7c on ID.