The arrest of convicted sex offender John Albert Gardner III in connection with the death of 17-year-old Chelsea King has prompted some outraged residents and lawmakers to call for a "one-strike" law for sex crimes.

But a law like that already is on the books, legal experts say.

Prosecutors and defense attorneys say a 1994 statute that was expanded and strengthened under Jessica's Law in 2006 is among the state's stiffest criminal sentencing provisions.

And some legal experts believe that Gardner, 30, could have been sent away for life under the law after a 2000 sexual assault on a 13-year-old girl in Rancho Bernardo.

Instead, he struck a plea bargain with prosecutors and served five years of a six-year sentence.

Gardner is in jail, charged with murder and rape or attempted rape in the death of Poway High School senior Chelsea King.

He also is the focus of the police investigation in the death of 14-year-old Escondido High School freshman Amber Dubois, whose remains were discovered last week after she had been missing more than a year.

A 1994 law

While some point to Gardner's sentence in their argument for a new one-strike law, many lawyers say current sentencing laws are powerful enough.

"I don't think the law is the problem," said Robert Fellmeth, a former San Diego County prosecutor who heads the Children's Advocacy Institute at the University of San Diego's School of law.

He said a law adopted by the California Legislature in 1994, designed to allow life sentences for certain sex offenses, is as strong a criminal law as any.

The sentencing gives child molesters and rapists sentences of 15 years to life or 25 years to life if the crime is committed under particular aggravating circumstances.

People convicted of molesting multiple victims qualify for life sentences under the statute, as do child molesters or rapists who inflict great bodily injury, kidnap or tie up a victim.

San Diego Defense Attorney Gerald Blank said prosecutors missed their chance to seek one-strike sentencing for Gardner's 2000 crime.

"That's what 667.61 is designed for; it fit him like a glove," Blank said, referring to the penal code.

According to court documents, Gardner took a 13-year-old acquaintance to his mother's Rancho Bernardo town house and assaulted her in several rooms of the house.

He allegedly punched her in the face and held her down, but she ultimately ran away.

Gardner also was charged with a misdemeanor for aggressively kissing and petting a 14-year-old girl months earlier, according to court documents.

Blank said with multiple victims and restraining the 13-year-old, prosecutors could have charged the case so Gardner qualified for a 15- or 25-years-to-life sentence.

The San Diego County District Attorney's office has declined to comment on the case.

One-strike qualifications

Sex offenders in San Diego County have at times been subject to the tough sentencing, though it isn't clear what guides the district attorney's decision to use it.

A gag order in the Gardner case means attorneys in the office won't comment on issues related to the defendant, spokesman Paul Levikow said.

In 2009, prosecutors charged defendants using the one-strike sentencing qualification 32 times, Levikow said.

By comparison, 172 people were charged with lewd acts on a child and 50 people were charged with rape, although it is not clear how many of them would have qualified for the sentencing enhancement.

Since 1994, the office has charged defendants with the one-strike enhancement 492 times, with 82 people ultimately being sentenced under the law, he said.

Even when prosecutors don't charge a sex offense so that it qualifies for a life sentence, their power to do so means they can demand relatively stiff sentences for first-time sex offenders, San Diego defense attorney Brian White said.

"It's always one of those things that is looming in the background," White said. "Let's say there is a client who has multiple victims; you have either express or implied threat of the complaint being amended to add the allegation."

That threat means child molesters can't easily bargain with prosecutors for a shorter sentence, the attorney said.

Case-by-case basis

Gerald Fineman, a Riverside County deputy district attorney who supervises a family protection unit for the southwest part of the county, said prosecutors there routinely use the sentencing provision to send child molesters to prison for life.

He pointed out that in California, sentencing laws allow "full, separate and consecutive" sentencing for sex offenders.

Although a robber charged with holding up four banks could get only the maximum sentence for one robbery count under California law, a child molester could get the maximum sentence on each count, or victim.

That means a Riverside County child molester with two victims was recently sentenced to two consecutive 15-year-to-life sentences, for a total sentence of 30 years to life, Fineman said.

"We use it frequently," Fineman said of the one-strike law.

He cautioned, however, that prosecutors maintain the discretion to choose when to apply the law.

And it is not always appropriate, even if a crime could legally qualify, Fineman said.

"It's a case-by-case basis, and it would have to do with the type of conduct and the length of time it occurred," he said. "Every case is different."

Some advocates for new one-strike laws think the case by case evaluation by prosecutors allows too many plea bargains and light sentences.

"That's still not what I consider a clear-cut, one-strike law," said Karen Doll-Murphy, 49, an Escondido mother who created a "Support One Strike Law for Sex Offenders" page on Facebook.

That page has more than 9,000 followers.

"If you molest or rape a child or rape an adult, you are a violent sex offender, and then, you should get life without parole," she said.

Call staff writer Sarah Gordon at 760-740-3517.