A South Dakota inmate has been executed for the 1990 rape and murder of a 9-year-old girl who disappeared after leaving her home to buy sugar for lemonade.

Sixty-year-old Donald Moeller received a lethal injection Tuesday night at the state penitentiary in Sioux Falls, marking the state’s second execution this month.

Moeller kidnapped Becky O’Connell from a Sioux Falls convenience store in May 1990, then raped and stabbed her. Her naked body was found the next day near the Big Sioux River.

Becky’s mother, Tina Curl, has been steadfast in her wish to watch Moeller die. She raised money so she could travel from her New York home to watch the execution.

Curl says Moeller watched her daughter take her last breath, and she wanted to watch him take his.