A cross-country team member, the 17-year-old enjoyed taking long runs, but by early evening she still wasn't home. Her father, Brent King, went to the parking lot near the trail head and found her car, still locked.
Something was definitely wrong.
"He started running down that trail looking for her," David Mikkelson, a family friend, said Monday.
Four days after her disappearance, the King family, along with hundreds of law enforcement authorities and volunteers, were still searching for the blond, blue-eyed girl. But their hopes of finding her alive dimmed after police arrested a registered sex offender Sunday evening outside a Mexican restaurant near the popular recreational area.
The suspect, John Albert Gardner III, 30, was jailed on suspicion of murder and rape after investigators found several pieces of unspecified evidence. He has not been charged. Gardner, 6 feet 2 and 230 pounds, pleaded guilty in 2000 to molestation charges involving a 13-year-old girl.
A psychiatrist at the time recommended that Gardner be given the maximum sentence, which was at least 10 years. San Diego County prosecutors recommended a six-year term. "It is my opinion that [the defendant would be a continued danger to underage [girls] in the community," said the psychiatrist in the court documents.
Authorities were not sure Monday how much time Gardner actually served in prison. According to the Megan's Law website, he lives in Lake Elsinore, in Riverside County, but was visiting his mother in San Diego County last week. At the time of his arrest, Gardner's pants were damp, authorities said.
It was not clear Monday if Gardner was providing any information regarding Chelsea's whereabouts. Authorities were focused on the 14 miles of shoreline of the shallow lake, where FBI dive teams on rafts scoured the murky water. Hundreds more volunteers searched the desolate trails winding around the lake.
"It's rugged terrain: sloughs, rocks, vegetation, hills. It's not easy, but it's not deterring them," said Jan Caldwell, a spokesman for the San Diego County Sheriff's Department.
Friends and relatives described Chelsea as an outgoing overachiever with a passion for literature who had been accepted to several colleges. She played French horn for the San Diego Youth Symphony and tutored other students.
Her parents, who live in a gated community, didn't like her to jog alone. It was one of the few rules they had to set for their daughter. "They wanted her to study less and have more fun," Mikkelson said.
Stephanie Dorian, a cousin, said Chelsea ran regularly, with no iPod -- "a purist," she said -- and kept a vegetarian diet as part of her healthful lifestyle. "She is as stellar as they come. . . . She is one of the perfect kids. I know it sounds cliche, but it's true," Dorian said.
The case prompted an outpouring of support in the middle-class community about 20 miles north of San Diego. Students at Poway High School wore blue shirts evoking Chelsea's blue eyes. A bank parking lot was turned into a search center where hundreds of volunteers were broken into teams and dispatched to different areas.
Among those searching was Maurice Dubois, 40, whose daughter, Amber, disappeared in the same area a year ago. He said investigators told him Monday that his daughter, who was 14 when she disappeared, might be one of Gardner's victims.
Dubois wants closure but dreads the possible outcome of the investigation, for the King family and for himself. "I don't want to find a connection, certainty after seeing what this monster is capable of," Dubois said.
In 2000, Gardner picked up an eighth-grader at a bus stop in San Diego County and assaulted her at his house, punching her several times after she tried to prevent him from pulling her pants down.
Gardner "was suffocating me. He had his hand on my mouth, and I couldn't breathe, and I got pretty fuzzy after he hit me, and I'm not sure if I blacked out," said the victim, according to the sentencing memorandum.
Prosecutors recommended a six-year prison term because Gardner had no criminal record, but they expressed concern.
"Defendant's lack of remorse in the face of overwhelming evidence of guilt and his prior admissions of committing the crime show that he can be expected to re-offend when he gets the opportunity to do so," said the prosecutor, then-Deputy Dist. Atty. David Hendren.