A small rural town in Missouri was shaken up after a man allegedly killed seven of his relatives and then himself during a shooting spree Thursday night.

Authorities believe Joseph Jesse Aldridge, 36, of Tyrone, Missouri, went on a door-to-door killing spree after he discovered the body of his 76-year-old mother, Alice Aldridge, who likely died from natural causes in their house, said Texas County Coroner Tom Whittaker.

According to Texas County Sheriff James Sigman, Joseph Jesse Aldridge died from an apparent self-inflicted gunshot wound. His body was found in his pickup in Shannon County, about 15 miles from Tyrone.

All of the murder victims lived within a few miles of each other in Tyrone, an unincorporated area with a population of about 50, authorities said. However, the shooter's motives remain unclear.

"It's heartbreaking," said Todd Haley, senior pastor at Ozark Baptist Church, about three miles from Tyrone, reports Reuters. "Anytime you see families that go to this level of violence, it's a shame."

On the night of the shootings, a neighbor said a teenage girl frantically ran to his home wearing a nightgown and no shoes around 10:15 p.m. She told him her parents had been shot. She then called police and deputies found her parents dead at their home.

That neighbor, who did not want to be identified, told the Springfield News-Leader the 15-year-old girl "was barefoot, in a nightgown with no sleeves at all and her legs were all scratched up from briars." He added, "She said she seen a man in her dad's bedroom, talking to him in a normal voice. Then she said she heard gunshots and screaming."

Over the next three hours, deputies found the bodies of a man and a woman at the first house then five more bodies at three more homes. In addition, one woman, who was hospitalized with multiple gunshot wounds, gave them information about the shooter. A 10-year-old boy also survived -- he was asleep in one of the homes during the shooting spree and was not injured.

Officials identified four of the victims as Garold Aldridge, 52, his wife Julie Aldridge, 47, Harold Aldridge, 50, and his wife Janell Aldridge, 48, reports USA Today. The names of the other victims were not released.

Sheriff Sigman said there was no sign of forced entry in any of the houses and that the killings have changed the sense of safety that town residents once had.

"Start locking your doors. The world is changing. You got to be safe," he said.