Around midday on 26 December, the remaining members of the family arrived for their Christmas visit. The first to be killed was Simmons’s son Billy and his wife Renata; both were shot dead. Then their son Trae was strangled and drowned, followed by their daughter. His oldest daughter Sheila who Simmon's had a insestious relationship with and her husband, Dennis McNulty, who were both shot dead. Ronald Simmons’s child by his own daughter Sheila, Sylvia Gail, was strangled, and finally his grandson Michael. Simmons laid the bodies of his whole family in neat rows in the lounge. All the corpses were covered with coats except that of Sheila, who was laid in state covered by Rebecca Simmons’s best tablecloth. The bodies of the two grandsons were wrapped in plastic sheeting and left in abandoned cars at the end of the lane. After the murders, Simmons went for a drink in a local bar, then returned to the house and, apparently oblivious to the corpses lined up around him, spent the rest of the evening and the following day drinking beer and watching television.
On the morning of Monday, 28 December, Simmons drove into Russellville, and at a law office shot dead the receptionist, a young woman named Kathy Kendrick, with whom he had been infatuated and who had rejected him. He next went to an oil company office where he shot dead a man named J.D. Chaffin and wounded the owner, Rusty Taylor, and then drove on to a convenience store where he had previously worked, shooting and wounding two more people. Afterwards he went to the office of the Woodline Motor Freight Company, where he shot and wounded a woman, ending his killing spree. Simmons simply sat in the office and chatted to one of the secretaries whilst waiting for the police. When they arrived, he handed over his gun and surrendered without any resistance.
Simmons was charged with sixteen counts of murder, found guilty, and sentenced to death. He refused to appeal his death sentence, stating, "To those who oppose the death penalty in my particular case, anything short of death would be cruel and unusual punishment."
While on Death Row, Simmons had to be separated from other prisoners as his life was threatened constantly. This was because he refused to appeal his death sentence. The other prisoners believed Simmons was damaging their chances of beating their own death sentence.