Later today, a man who's admitted to raping and killing two San Diego-area teenage girls will be sentenced to life in prison without parole.
Some say the murders of Chelsea King and Amber Dubois could have been prevented had the state had tougher sanctions on sexual predators. But others question whether stricter laws make a difference.
California voters approved a crackdown on sexual predators in 2006. Jessica's Law severely restricts where a registered sex offender can live. It also mandates lifetime electronic monitoring of felony sex offenders.
Cynthia Calkins Mercado is an assistant professor of psychology at the John Jay College of Criminal Justice in New York. She says measures like Jessica's Law may placate the public, but their effectiveness is limited.
"The studies that have been done," Mercado says, "seem to show that if anything, they're creating a lot of problems or collateral consequences that could even have the paradoxical effect of increasing, rather than decreasing, risk of future offenses."
For example, Jessica's law did not provide any money. As a result, only about ten percent of sex offenders in California are being monitored. Restrictions on where predators can live have driven some into homelessness.
In light of the Chelsea King murder, a new measure has been proposed. Under Chelsea's Law, prosecutors could seek life in prison without parole for forcible sex crimes against a minor.
Rehabilitation is another option. Some say treatment can help change predators' behavior.
Dr. Saul Levine is a professor of clinical psychiatry at UCSD.
"The long-term follow-ups of a lot of the studies, that have been done for various kinds of psychological interventions, all have equivocal results," said Dr. Levine. "Meaning that there's no prediction than once you've gone through this, that that particular perpetrator that has been labeled already, is not gonna do it again."
There are some medical treatments designed to reduce sexual urges. Levine says studies indicate the treatments can be effective, as long as a person stays on the medication. But it's like managing other chronic conditions -- once you stop the treatment, the patient lapses.
"There have been some terrible cases of that where there's expectation that this individual has learned his or her lesson, has controlled their impulses, has gotten over their obsessions, goes off the medication and reverts, and something terrible happens," Levine points out.
Nonetheless, treatment professionals say even some violent sex offenders who go through extensive therapy can be rehabilitated.
Pedophiles are a different story.
David Peters is a therapist in private practice in San Diego.
"Pedophiles will pretty much always have a sexual arousal toward pre-pubescent children," Peters says. "And while they may be controlled, they won't be cured, and they have to be monitored, really, for the rest of their lives."
Forensic psychologist Dawn Griffin is a program director at Alliant University. She agrees if you lock up a sexual predator for life, you've solved that individual problem. But…
"What have we learned from him?" Griffin ponders. "Why did he begin offending? The more we can understand that dynamic, the better I think we can apply it into treatment standards, into assessments, the better, more holistic understanding we will have as to why individuals offend."
Griffin believes the key to that understanding is treatment.
Here's one thing to keep in mind, however: Up to 90 percent of sex offenders are related to or know their victims. That means that strangers who abduct and murder young girls are rare.
So why do we concentrate on these infrequent crimes?
"Because it's a little safer, quite honestly, dealing with a stranger rape, and abduction and killing, rather than taking a look at a family dynamic and saying, a father did this to his child, or a mother did this her child," Griffin responds. "That's really tough for all of us to wrap our head around."
In fact, Griffin says even if we locked up all convicted sexual predators for life, we wouldn't put an end to the vast majority of sexual offenses.