HONDO, N.M. - ABC newsman Sam Donaldson described Delbert Paul Posey, his wife and children as an all-American ranch family. So Donaldson knew something terrible had happened at his Chavez Canyon Ranch in New Mexico when he went to check on the family and discovered what Lincoln County Sheriff Tom Sullivan called an "obvious crime scene."

After deputies found three bodies in a shallow grave on the ranch, Posey's 14-year-old son, Cody, was arrested Wednesday on charges of killing his father, stepmother and stepsister, authorities said. An initial court appearance was scheduled for Thursday, Sullivan said.

...The Donaldsons were in Santa Fe in northern New Mexico during the Fourth of July weekend, when the slayings apparently occurred. Sullivan said the case is still being investigated but it appeared the three had been shot Saturday.

"We didn't see them Tuesday morning or Tuesday afternoon, so I went over - and on the porch was a large stain that was instantly recognizable," Donaldson told Albuquerque television station KOB-TV.