A teen about to graduate from high school shot to death his grandparents, mother and two friends, then wounded his younger sister before committing suicide, authorities said Monday. The rampage perplexed school officials, who said he seemed to have been in good spirits.

Logan County (search) Sheriff Michael Henry said Monday he did not know if authorities would ever find out why Scott Moody (search) acted as he did, "but we're going to try."

The shootings at two neighboring farmhouses were discovered when the sole survivor, Moody's critically wounded teenage sister, called her stepsister, who made an anguished call to 911. The deaths came hours after a family party to celebrate graduation.

Preliminary evidence showed that Moody went to the farmhouse next door sometime Sunday morning and killed his grandparents with a .22-caliber rifle, then returned home, where he shot the others, then himself.

Bernie Pachmayer, superintendent for the school district, said no one had seen any indication Moody was troubled. He was looking forward to graduation and was in great spirits, she said.

"In our minds, it couldn't possibly be Scott," Pachmayer said.

She said he was a clean-cut boy who wanted to farm and fit well into the area when he came to the district two years ago.

"He was a farmer at heart," she said. "He worked the land."

Henry identified the victims as Moody's grandparents Sharyl Shafer, 66, and Gary Shafer, 67; Moody's mother, Sheri Shafer, 37; and two friends, Megan Karus, 19, and Paige Harshbarger, 14. Karus and Harshbarger had slept over after the party.

The bodies of Moody's mother and the two friends were discovered in the other home along with the wounded survivor, Stacy Moody, and the body of Moody himself. Authorities said Karus was on the couch. The other victims were in upstairs bedrooms.

Stacy Moody, 15, was shot in the neck. She remained in critical condition Monday at Ohio State University Medical Center.

There was no sign of a struggle at either house, Henry said, adding that it appeared Karus, Harshbarger and Sheri Shafer were killed while they slept.

The houses are about a quarter-mile apart along a two-lane state route a mile west of the city of 13,000 people, 45 miles northwest of Columbus. Fields where corn and soybeans are grown surround the white-paneled, two-story homes.

Authorities were alerted to the slayings after Stacy Moody called her stepsister, Nicole Vagedes, telling her that she and her mother had been beaten up and that she could not wake up her mother.

Vagedes went to the house and called 911. "I can't wake her," she said of the mother, Sheri Shafer. "I can't get a pulse."

Her voice became more frantic as she told emergency dispatchers about finding bodies throughout the home.

"Oh my God, there's one in the living room. There's another one on the couch," Vagedes told deputies in an anguished 911 call that was released Monday.

Henry said the sheriff's office had received nuisance calls about loud music and parties at the house, but he did not know whether the complaints were about Scott Moody.

"It's tough on us," Henry said of the shooting. "We knew these people. We're familiar with these kids. I feel so badly for these families, this community."

Moody and Karus were to have graduated Sunday afternoon from Riverside High School (search) in nearby De Graff. School officials, who had only minutes of notice about the deaths before the ceremony began, held graduation as scheduled and announced the shootings afterward.

Two seats remained empty at the commencement.

Last week, Moody's family had taken out two congratulatory ads featuring Moody's picture in the Bellefontaine Examiner. The ad from his mother and sister read "Good luck and have fun!"

Brandon Stewart, 16, a year behind Scott Moody and Karus at Riverside High School, said students at the small school all knew one another and that everyone got along with the four students who were shot.

"None of them seemed like troublemakers," Stewart said.