Nieves was born in 1964. On June 30, 1998, at her home in Saugus in Los Angeles County, she gathered her four daughters in the kitchen, put mattresses on the floor, and set a fire: Jaqlene Folden, five; Kristl Folden, seven; Rashel Nieves, eleven; and Nikolet Nieves, twelve. All four died of smoke inhalation. Her son survived, having been elsewhere in the house.
She was convicted of four counts of first degree murder and sentenced to death on October 6, 2000.
On May 3, 2021 the Supreme Court of California, on the automatic appeal that follows every California death sentence, affirmed her convictions and reversed the death sentence, in a judgment unusually blunt about the conduct of the trial. The court found that the trial judge had made disparaging and sarcastic remarks to defence counsel in front of the jury, had sanctioned and cited him for contempt in the jury's presence, had belittled a defence witness and openly doubted the credibility of a defence expert. Chief Justice Tani Cantil-Sakauye wrote that the misconduct could not have altered the jury's finding of guilt, but that the court could not reach the same conclusion about the penalty trial. The murder convictions stand and the death sentence is gone.
The case is in the archive as a single act, not a serial one. It is also one of the clearer examples in the American record of an appellate court setting aside a death sentence because of what a judge did rather than what the lawyers failed to do.