SAN DIEGO — When 17-year-old Chelsea King disappeared in a park last week, authorities checked photographs of sex offenders registered in the San Diego area. John Albert Gardner III was not among them.
When a 16-year-old girl was attacked last year in Riverside County, authorities did a similar check of the sex offender registry. Again, Gardner was not among them.
In both investigations, Gardner eluded detection because he was registered as a sex offender in different counties.
As authorities search for Gardner's possible links to other cases, his trail highlights how sex offenders in California manage to avoid suspicion even under a system designed to keep close tabs on the state's most dangerous predators.
"Obviously there's loopholes and he seems to have found them, either by design or by happenstance," said Marc Klaas, who founded Klaaskids Foundation after his 12-year-old daughter Polly was abducted from a slumber party in 1993 and later found slain.
Gardner has attracted national attention ever since he was arrested in the rape and killing of King, a 17-year-old straight-A student whose body was believed to have been found in a shallow lakeside grave Tuesday.
Gardner, 30, is being held without bail after pleading not guilty Wednesday to Chelsea's murder and to attempted rape of another woman in December, a potential death penalty case. His public defender, Michael Popkins, did not address reporters after the arraignment.
Escondido police are also investigating if Gardner is tied to the disappearance of Amber Dubois, a 14-year-old who vanished a year ago while walking to school and carrying a $200 check to buy a pet lamb.
No suspects have ever been publicly identified.
"This has definitely got our attention," said Lt. Craig Carter.
Gardner was registered as a sex offender because of his 2000 conviction for molesting a girl after luring her to his house with the Robin Williams movie "Patch Adams," about a doctor who uses humor to treat patients. He served five years of a six-year sentence, though his plea agreement allowed for nearly 11 years and a court-appointed psychiatrist urged "the maximum sentence allowed by law."
Gardner was a registered sex offender in Escondido, in San Diego County, from January 2008 to January 2010, with some gaps, Carter said. On Jan. 7 of this year, he registered as a sex offender 55 miles north in Lake Elsinore, in Riverside County.
Seven weeks later, King disappeared in San Diego, and Gardner's name didn't turn up on the list of neighborhood sex offenders because he had already registered that he moved north.
Authorities are also investigating the case of a 16-year-old girl who reported that she ran away after a man asked her for directions then tried to force her into a car at gunpoint on Oct. 28 in Lake Elsinore, the Riverside County Sheriff's Department said.
The suspect was described as a man 30 to 35 years old with a squarish jaw, brown eyes and a blond crew cut. A sketch appears similar to Gardner.
"There are similarities," Capt. Joseph Cleary told the Riverside Press-Enterprise. "If there is a connection, we will track it down."
Investigators checked out local sex offenders at the time, but not Gardner; he was registered as living in San Diego County, Sgt. Patrick Chavez said.
"He had not come onto our radar until January," when he notified authorities that he was living in an unincorporated village near Lake Elsinore, Chavez said.
California has required sex offenders to register with local police for 50 years, and began making the information available to the public in the mid-1990s. It now posts information about more than 63,000 offenders online through what's known as the Megan's Law database, named after a 7-year-old New Jersey girl killed by a child molester who had moved in nearby.
Gardner is not subject to Jessica's Law, which bars offenders from living within 2,000 feet of a school or park and is supposed to require lifetime GPS monitoring of their whereabouts. California voters approved the law in 2006, after Gardner was paroled.
Brent King, Cheslea's father, declined to address shortcomings in how Gardner and other sexual predators are tracked.
"In due time, I'm going to have a lot to say about that," he said in a brief interview Thursday. "Now is not the right time. We need to heal first."
King said he was deeply thankful to law enforcement and volunteers who mounted a massive search for Chelsea and "every person who said a prayer for us."
"Thank you is not enough to say," he said.
Investigators are still trying to determine if Gardner is connected to the disappearance of Amber Dubois.
Her father, Maurice, believes there is a strong possibility that Gardner abducted his daughter, a few miles north of where Chelsea disappeared. He noted Amber and Chelsea had similar builds.
Amber, a member of Future Farmers of America, left home with $200 check to buy a lamb. It was never cashed.
"She was so excited to get to school that morning it was incredible," said Dubois, an electrical engineer near Los Angeles.
Don Thompson reported from Sacramento, Calif.