Woman to watch daughter's killer die in South Dakota SIOUX FALLS, S.D. - Becky O'Connell left her South Dakota home on a simple errand: to go to the store for sugar so she could make lemonade. When the 9-year-old didn't return that day in 1990, panic gripped Sioux Falls. Parents kept their children indoors until the mystery could be solved. And within hours, it was -- with a gruesome outcome: Becky had been kidnapped, raped and stabbed to death. Becky's killer, 60-year-old Donald Moeller, is set to die Tuesday night by lethal injection in South Dakota. Her mother, Tina Curl, has been steadfast in her wish to watch him die, raising money so she could make the 1,400-mile trip from her home in New York. She says Moeller watched her daughter take her last breath, and she wants to watch him take his.