(CNN) — John Lajeunesse said he was heading to Renegade Mountain to go four-wheeling, nothing out of the ordinary for a 16-year-old kid in rural Tennessee.
How he and three other young people ended up shot dead inside a car on that same mountain is now a mystery before police and the small community of nearby Crossville.
A passer-by discovered the car with the four victims, including a young mother, on Thursday.
Lajeunesse and a pair of 17-year-olds, Steven Presley and Dominic Davis, were the passengers. Danielle Jacobson, 22, was in the driver's seat.
Three of the victims were current or former students of the local school district.
"This is something traumatic that has never happened before in our county," Cumberland County Sheriff Butch Burgess said.
Authorities have named a lone suspect: Jacob Allen Bennett. Bennett has not been charged in the killings but was arrested on an unrelated charge as investigators continue their work.
The local community "can rest assured that we believe that we have this person that committed these crimes in custody," Tennessee Bureau of Investigation Director Mark Gwyn said.
"We identified him as a suspect pretty quickly," he added.
If law enforcement authorities know more, they kept the facts close to the vest Friday.
Michael Rick, who lives with Lajeunesse's family, said he dropped the 16-year-old at Presley's house on Wednesday afternoon.
Lajeunesse mentioned that the pair were going to go four-wheeling at the mountain and spend the night at his friend's house.
The next day, Lajeunesse didn't call Rick to be picked up.
"You just get that gut feeling when nothing is right," Rick said.
It wasn't until Thursday night that police were able to confirm what they feared: Lajeunesse was among those killed.
According to the Cumberland County Board of Education, Lajeunesse was a former student at two local high schools who most recently was home-schooled.
The teen loved to skateboard and wanted to spend more time hunting, Rick said.
Lajeunesse was very loving toward his family, dedicating himself to his mother, sister and baby niece, Rick said.
"He was only 16. He was just getting out to live life," he said.
A friend of Jacobson's said the 22-year-old lived for her son.
"She loved her little boy more than life itself. She talked about her child a lot. That's what saddens me the most," said the friend, who asked not be named because they had not been friends for too long.
Jacobson was not shy.
"She was very nice, she was innocent, and she couldn't stop talking," the friend said. "She had something to say about every topic."
The two other victims, Presley and Davis, were also locals.
Davis was a student at Cumberland County High School, and Presley graduated from Phoenix High School just months ago.
Crossville is a small town, and along with messages of condolence, rumors of what might have happened also began to spread.
Was it a drug deal gone bad? A theft? A fight? Residents want to know, but police refuse to speculate.
"There's a lot of emotion that goes into this case just simply based on the age of these children," said Casey Cox, the chief investigator for the sheriff's department.