Investigators search for what triggered Missouri rampage

By Kevin Murphy and Carey Gillam KANSAS CITY, Mo. (Reuters) - What led Joseph Aldridge to gun down seven people in a southern Missouri hamlet remained uncertain on Saturday, though authorities speculated that the death of the gunman's mother from cancer could have triggered the rampage. Aldridge, 36, embarked on a shooting spree late on Thursday in the rural community of Tyrone, going door-to-door in the wintry night, killing four relatives and three neighbors, and wounding another, before fatally shooting himself, police said. The massacre unfolded shortly after Aldridge's mother, 74-year-old Alice Aldridge, died from complications of metastatic lung cancer. Texas County Coroner Tom Whittaker said an autopsy revealed the fatal condition. Whittaker said Aldridge may have been triggered to carry out the killings by the discovery of his mother's body, but he added that authorities were considering other possible explanations. "Why it went to this extent, we don't know and I don't know that we ever will," he said. Most of the victims were found in their bedrooms, according to Whittaker. At least two children in two separate homes escaped injury while their parents were slain, according to the Texas County Sheriff's Office. One of the children, a teenage girl, fled to a neighbor's house where she called police. Her parents, Garold Aldridge, 52, and his wife Julie Aldridge, 47, were found dead in their home, the sheriff's office said. Harold Aldridge, 50, and his wife Janell Aldridge, 48, were discovered dead in a separate residence. Garold and Harold were cousins of Joseph Aldridge. The other three killed were members of prominent family that ran businesses in the region, including a cabinet making shop, a cattle ranch and an auto dealership. Authorities said they were Carey Shriver, 46, his wife Valirea Shriver, 44, and Carey's father Darrell Shriver, 68. Darrell's wife Martha, 67, was wounded but survived, Texas County Sheriff James Sigman said in a statement on Saturday. Martha Shriver frantically called the home of her husband's cousin, John Shriver, because her husband was shot, said John's wife, Nora, in a phone interview on Saturday. John Shriver went to the house, finding Carey and Valirea Shriver dead on the floor, Nora Shriver said. Their 13-year-old son was asleep in his room and unharmed, she said. "They were good, hard-working people who tried to keep their nose clean," Nora Shriver said. "It's hard to accept and hard to figure out." There was no sign of forced entry in any of the houses where the shootings occurred, said Sigman, adding that the killings had shattered a sense of safety in the town. A review of court records shows Aldridge had a history of using drugs. In 2008, he was sentenced to 21 months in federal prison for possessing a handgun while using marijuana, and was ordered to undergo mental health and substance abuse counseling, court records show. Tyrone, an incorporated community with about 50 residents, is about 160 miles southwest of St. Louis, near the Mark Twain National Forest, in an area that attracts hunters, campers, and river rafters. (Reporting by Kevin Murphy in Kansas City; Additional repoting by Carey Gillam in Kansas City; Editing by Alex Dobuzinskis, Bernard Orr)