Christina Marie Riggs was born Christina Marie Thomas on September 2, 1971, in Lawton, Oklahoma. She grew up in Oklahoma City. During her childhood, she faced challenges, including claims of sexual abuse. By the time she was 14, she started using alcohol, tobacco, and marijuana.

At 16, Christina became pregnant for the first time and chose to give the child up for adoption. After finishing high school, she trained to become a licensed practical nurse. She worked in various healthcare settings, including home health nursing and a Veterans Administration hospital.

In 1991, she became pregnant with her son Justin. The father of the child was not part of their lives. Before Justin's birth in June 1992, Christina began dating Jon Riggs. They got married in 1993 and had a daughter named Shelby in December 1994. The family moved to Sherwood, Arkansas, in 1995, to be closer to Christina's mother. There, she started working at Baptist Hospital. However, Christina and Jon eventually divorced after he was accused of hitting Justin.

Christina Marie Riggs killed her two children, Justin Dalton Thomas, age 5, and Shelby Alexis Riggs, age 2, in their beds at their home in Sherwood, Arkansas, on November 4, 1997. Riggs planned to use a combination of injectable potassium chloride, amitriptyline sedative pills, and morphine to commit the murders. She obtained the amitriptyline from a pharmacy and stole the other two drugs from the hospital where she worked.

Riggs injected her son Justin with potassium chloride first. The medication caused him severe pain but did not kill him. In an attempt to ease his suffering, she tried to give him morphine, but it was ineffective. Ultimately, she smothered him to death. She then smothered her daughter Shelby, opting not to inject her after witnessing her son’s pain. After the murders, Riggs laid the children on her bed, covered them with a blanket, and wrote suicide notes.

Riggs then attempted to take her own life by ingesting 28 amitriptyline pills and injecting herself with potassium chloride. Nineteen hours later, her mother found her unconscious on the floor of the home.

Riggs stood trial in June 1998. She claimed not guilty by reason of insanity, citing depression and trauma from her job as a nurse. However, prosecutors argued that she acted out of hatred for her children. The jury convicted her of capital murder. During sentencing, Riggs decided not to have a defense presented. She later waived her appeals and was held on death row.

Riggs was executed by lethal injection on May 2, 2000, at the Cummins Unit in Arkansas. She was the fifth woman executed in the United States since the death penalty was reinstated in 1976 and the first woman executed in Arkansas since 1845. Before her execution, she expressed deep sorrow for her actions.