Christina Marie Riggs (September 2, 1971 – May 2, 2000) was a murderer executed in Arkansas by lethal injection. She was convicted of the November 4, 1997, murder of her two young children, Justin Dalton Thomas and Shelby Alexis Riggs. The children were killed in their beds at the family’s Sherwood, Arkansas home. The murder plan involved giving the children undiluted potassium chloride just after giving them amitriptyline to sedate them. However, the potassium chloride was not diluted properly and it burned her son’s veins, causing Justin terrible pain but not death. She eventually smothered him when the injection was ineffective. She then smothered her daughter Shelby, without injecting her, after seeing the pain that the drug caused Justin. She laid the children on her bed, covered them with a blanket, and wrote suicide notes. She then attempted suicide by taking twenty-eight amitriptyline pills and injecting herself with undiluted potassium chloride. Nineteen hours later, Riggs’ mother discovered her unconscious on the floor of her home.  Riggs’ defense said she was suffering from depression and apparently did not want to have her children split up after her envisioned suicide. The children had different fathers.  At her June 1998 trial, Riggs contended she was not guilty by reason of insanity, but the Pulaski County jury convicted her. During the penalty phase, Riggs would not allow attorneys to put on a defense, saying she wanted a death sentence. She was executed with a potassium chloride injection, the same substance with which she attempted to kill her children.

Riggs was placed in the Arkansas Department of Correction system and held at the McPherson Unit, which included the female death row, until her execution. The Arkansas execution chamber is located at the Cummins Unit.  On Sunday April 30, 2000, Riggs was flown from McPherson to Cummins in preparation for her execution. She was executed at 9:28 pm Central Daylight Time on May 2, 2000. Riggs was the fifth woman executed in the United States since the reinstatement of the death penalty in 1976. She was the first woman executed in Arkansas since 1845. Her statement before execution began: “No words can express just how sorry I am for taking the lives of my babies. No way I can make up for or take away the pain I have caused everyone who knew and loved them.” Her last words were, “I love you, my babies.”