Rickey Lamb told investigators he went to his son Chris Lamb's residence south of Joplin on Monday to try to scare him out of any effort to assume custody of his children.
He took his .30-06 rifle with him for protection because he knew his son had a shotgun, he told investigators.
They had been arguing over the phone that morning about his son's and Sarah Tyminski's children. The children had been in Rickey Lamb's custody for about a year. In the course of their argument, his son had threatened to keep the children the next time he and Sarah got them for a visit, he told the investigator.
Rickey Lamb told investigators that he simply intended to scare his son out of ever attempting that when he went to the couple's home at 8571 Eloise Lane armed with a rifle Monday morning.
But when the confrontation of father and son ended, Tyminski, 32, lay dead in her front yard, a round from the .30-06 apparently having passed through her hand and into her abdomen. Chris Lamb, 35, suffered a gunshot wound to the chest and was taken to Mercy Hospital Joplin in critical condition.
And Rickey Lamb drove to his home on Apricot Drive with a shotgun wound to his shoulder, for which he was later treated at Freeman Hospital West before being released to the custody of deputies Monday afternoon and placed under arrest.
The Newton County prosecutor charged the 60-year-old rural Joplin man on Tuesday with first-degree murder, first-degree domestic assault and two counts of armed criminal action. He was being held at the Newton County Jail on a $500,000 cash-only bond pending an initial court appearance.
A probable-cause affidavit filed with the charges states that he told investigators that his son shot at him first when he pulled into the couple's driveway. He said Chris Lamb knelt down behind a tree and fired his shotgun at him. The suspect said he grabbed his rifle and shot his son, causing him to drop his shotgun.
Rickey Lamb told an investigator that Tyminski tried to pick up the shotgun, so he shot her. His son picked up the shotgun and shot at him a second time, this time hitting him in the shoulder.
But a witness to the shooting provided a decidedly different account of events, according to the affidavit.
Teresa Brown, a co-occupant of the address with Chris Lamb and Tyminski, told investigators that she heard Chris arguing with his father about the children over the phone. She said Rickey Lamb pulled up to the house later and started shooting. He had already shot his son and Tyminski when Chris Lamb grabbed his gun and shot his father, she told investigators.