(CNN) -- They were sons and daughters, with their whole lives ahead of them. Until -- for reasons no one has yet explained -- their lives came to a horrific, bloody halt on a rural road on Tennessee's Cumberland Plateau.
Dominic Davis, 17
Davis was new to Tennessee, having recently moved from Colorado with his family "to make life better," Cumberland County's school district explained in information distributed to the media.
But in his short time here, school superintendent Donald Andrews told CNN, "They had endeared themselves to the community."
A sophomore at Cumberland County High School, where he was well-liked and respected, Davis loved art, music and sports, especially basketball.
Academically, his goal was modest -- to pass all his classes with at least a C. But in life, as he wrote in a class assignment, it was deeper and loftier: "I want to be remembered not as the best man alive, but the most respected."
Steven Presley, 17
Presley used to miss class often. But his attendance was perfect after transferring to The Phoenix School, where he stood out -- and was singled out -- as an example that students could change and improve their lives.
And Presley made others' lives better in the process. The school district described him as "always happy, smiling, funny, kindhearted, sweet and polite," the type pf person "who would do anything for anyone (and) was loved by all who knew him."
He graduated from The Phoenix School in May. By then, Presley had already made a big impression with people from all walks of life who were lucky enough to cross his path.
"He reached out to those that no one else would," according to staff cited by the school district, "and treated everyone as a friend."
John Lajeunesse, 16
Lajeunesse had attended Cumberland County and Stone Memorial High School before settling in more recently as a home-schooled student.
Outside of academics, his interests weren't atypical for a teen growing up in rural Tennessee. He liked to go four-wheeling, loved to skateboard and wanted to spend more time hunting than he could, said Michael Rick, who lives with his family.
Rick described Lajeunesse as very loving toward his family, dedicating himself to his mother, sister and baby niece.
If he'd lived one month more, Lajeunesse would have turned 17. But for reasons those close to him are grappling to fathom, his loved ones are now mourning instead of celebrating.
Said Rick: "He was only 16. He was just getting out to live life."
Lajeunesse's younger sister, Katie, said she would miss the usual brother-sister stuff, like arguing with him.
"He never stayed in one place. He was always on the go," Katie, 15, said. "He was sweet, he made it fun."
Rikki Jacobsen, 22
The Cumberland County school district offered the least information on Jacobsen, beyond that she was the mother of a student attending an elementary school in the system.
That child, a son, was Jacobsen's life, according to a friend.
"She loved her little boy more than life itself," said the friend, who asked not be named because they had not been friends for too long. "She talked about her child a lot. That's what saddens me the most."
In fact, Jacobsen was chatty.
"She was very nice, she was innocent, and she couldn't stop talking," her friend said. "She had something to say about every topic."