Search and rescue crews from the Sonoma County Sheriff's Office continued searching on Friday about 10 acres of wooded terrain near Sonoma State University, where an 18-year-old's body was found in a shallow grave.
They were scouring the area for links to who might have killed Kirk Ryan Kimberly, whose body was found by a landscaper Wednesday afternoon.
He had been missing since Oct. 17, when he was last seen leaving Cotati on his white bicycle to meet a friend in Rohnert Park, according to the Cotati Police Department.
NBC Bay Area has learned that he graduated from Rancho Cotate High School in Rohnert Park last year, and the principal said counselors will be there on Friday for grieving students. This school is in the same district where two young sisters, ages 7 and 9, died in the Petaluma River in September.
Kimberly's friend Gema Ramirez described the teen as having ""a really humble smile and bright eyes."
For the last three days, Ramirez said she kept hoping it wasn't her friend who had died.
But her worst fears were confirmed Thursday night.
"I hope that he wasn't in pain," Ramirez said.
Having known Kimberly since fifth grade, Ramirez said it wasn't like him to just take off like that.
"I don’t know anyone who would want to hurt him," she said of the teen, who was working at a local pizza shop since completing school.
Who would have killed Kimberly and why has not been revealed. However, the preliminary cause of death "is at the hands of another," the sheriff's office said, and investigators are treating it as a homicide.
"I think he was having some issues, some personal issues," said Sgt. Spencer Crum.
When NBC Bay Area approached the Kimberly family home on Friday, someone from behind the door asked for privacy.
A family friend said the teen's parents had been holding out hope that Kimberly would come home alive.
"As of yesterday, they did not know that the body was his," said Linda Williams. "Great family, great neighbor, wonderful kid."
Anyone who has information about Kimberly’s disappearance or has knowledge of the incident is asked to call Detective Horsman of the Sheriff’s Violent Crimes Unit at 707-565-2185.