John Finley Scott, a 72-year-old retired sociology professor at UC Davis, has been missing 99 days. Based on what Yolo County sheriff's investigators found at the missing man's home, friends and family fear what may have happened to him.
After sheriff's investigators turned the house over to Scott's family, his friend Vance Sprock saw the disturbing evidence: blood.
Sprock said he was overwhelmed by grief when he saw the spatters, stricken that his friend may have encountered violence. Sprock has known Scott for 32 years and bought the Cupertino Bike Shop from him.
"It was almost surreal, like a dream," he said. "The reality is yes, it did happen, and it's tragic."
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Yolo County Sheriff's Capt. Larry Cecchettini said the case hasn't been classified as a homicide.
"We have no body," said Cecchettini. "But the family is prepared for the worst news.
"Significant physical evidence was found that leads us to believe he sustained injury."
Scott is considered a pioneer in mountain biking, a noted sociologist and a spirited contrarian.
He rode his bicycle from his house on the outskirts of Davis to the university June 1 to attend a party. Friends said he was in high spirits, joking and grinning for photos.
He e-mailed a friend June 3. Since then, no one has seen or heard from him. Friends reported him missing June 11.
Cecchettini said detectives arrested a man who was suspected of stealing a trailer from Scott's property, but the charges were later dropped. The trailer was on Scott's property when sheriff's detectives initially searched there. It was later found empty in a rural field.
The man is currently in custody for a parole violation; Cecchettini declined to name him.
"We're not ruling him out, but we don't have anything to charge him on," Cecchettini said.
Detectives have noted activity in one of Scott's bank accounts and are investigating the lead, Cecchettini said.
Scott had no children, but was dedicated to his sister and her two daughters who grew up in Colorado, said niece Cathy Clark of Hawaii.
"I loved him very much," Clark said. "Anything that involved family -- he was there."
Friends say Scott's disappearance deprives them of an intellectual who savors the role of devil's advocate and a cyclist who takes a place in the sport's history.
Scott was among the first people to outfit a road bike with balloon tires and low gears and hurtle down mountains.
"You can call him the inventor of the mountain bike, as far as I know," said Scott's friend John Schubert, a consultant to the cycling industry based in Pennsylvania.
Schubert said Scott effectively lobbied the California Legislature in the mid-1970s to treat the bike like a car rather than a pedestrian in regard to traffic laws.
He loved to take long cycling trips -- but he rejected the notion that bike transit could replace auto traffic.
"He'd walk into a room of true believers and tell them they were smoking something too powerful," Schubert said.
"His willingness to make fun of his sacred cows was his principal mode of eccentricity."
Friend Ben Timmons, a systems analyst who used to work in the UC Davis sociology department, said Scott wrote a well-regarded text in sociology.
The scholar delighted in rough-and-tumble debate, for instance, defending Richard Nixon to a group of liberal Democrats.
"He liked to throw a rock in a bush to see what comes out," said Timmons.
Scott lived in a clutter-strewn ranch house across County Road 98 from the university's Primate Research Center.
A gutted London double-decker bus sits on his driveway, surrounded by three dusty white Suzukis and bike parts.
Timmons visited the home Friday, where he casually kicked a tarp lying at the rear edge of the backyard.
"I hope we find him one way or another," Timmons sighed.