Texas Man Accused in Wife, in-Laws Stabbing Deaths A man accused of stabbing his estranged wife and her parents to death in a Dallas home was arrested Thursday as he pulled away from a fast food restaurant where officers tracked him after the killings, police said. William Palmer, of Sachse, confronted Donya Palmer outside her parents' home Thursday morning before following her inside and fatally stabbing all three, Dallas Police Lt. David Pughes said. William Palmer, 50, has been charged with capital murder and was being held on $1 million bail at the Dallas County Jail, where officials did not know if he had retained an attorney. Donya Palmer's sister also was hurt in the attack but was able to flee to an upstairs bedroom with her 6-year-old daughter and call police, Pughes said. Donya Palmer, 47, and her parents - Mary Davis, 67, and Raymond Davis, 69 - were pronounced dead at the scene. Pughes said William Palmer and his wife had separated a week earlier, but declined to offer a possible motive for the slayings. Authorities found no history of domestic violence between the couple. "It's impossible to provide an explanation as to what might be going through somebody's mind or what might cause somebody to snap and commit an act as heinous as this," Pughes said. It's unthinkable. Officers tracked Davis to a Taco Bueno restaurant about 15 miles away in Sachse, just outside of Dallas, and arrested him as he pulled out of the drive-thru. Taco Bueno manager Dolores Villa said Palmer was a regular customer who ate at the restaurant about three times a week. She said Palmer paid about $3 on Thursday for a sausage breakfast burrito and a soft drink. "He looked like he wanted to hurry up," Villa said.