The disappearance of Dru Sjodin (search) and the arrest of a convicted rapist suspected of kidnapping the 22-year-old University of North Dakota student raises a delicate question: Should convicted sex offenders ever be allowed to leave prison?

Some in North Dakota and Minnesota, where Sjodin grew up, are angry that Alfonso Rodriguez Jr. (search) was ever let back on the streets following his 23-year sentence for an attempted kidnapping and assault of a woman in Crookston, Minn., in 1980.

"Somebody like him [Rodriguez] should have never gotten out of prison — that is a menace to society," said victims advocate Kathy Redmond. But "until society gets a grip on the fact that there are sexual predators out there and they have tens of victims, it's not going to change."

But others say sex offenders can't simply be locked up for life if they've done their time.

"To be fair, you can't lock people up for crimes they may commit in the future," said Fox News legal analyst Lis Wiehl.

The search continued Thursday for Sjodin, who went missing from a Grand Forks, N.D., mall parking lot on Nov. 22. Rodriguez, 50, a three-time convicted rapist, had a bond hearing Thursday, where he said through his lawyer that he wants to remain in custody for his own safety.

Rodriguez was released from prison in May after serving his sentence. He has a history of sexual contact and attempted kidnapping with adult women, including a guilty plea to aggravated rape in 1975. He has used a weapon in at least one assault.

He is considered a Level Three sex offender in Minnesota, meaning he is believed to be at the highest risk of committing another sex crime.

Although sex offenders are required by federal law to register with local law enforcement whenever they move to an area or change jobs so that their whereabouts are recorded in state sex offender registries, many say a predator of this type shouldn't be freed to begin with.

"We wouldn't have had the two convictions afterward and Dru wouldn't be missing now" if Rodriguez was kept in jail, said Tracy Oetting, founder of Citizens for a One Strike Law (search), which advocates life sentences without the possibility of parole for the "most heinous" acts, such as raping children, the mentally disabled and the elderly.

And the rate of recidivism — the commission of more offenses — may be fueling this argument.

Studies conducted by the Bureau of Justice Statistics (search) prior to 1997 found that convicted rapists were found to be 10.5 times as likely as those who had no rape records to be arrested on violent sexual assault charges. And people who served prison time for sexual assault were 7.5 times as likely as those convicted of other crimes to be arrested again for new assaults.

Another Justice Department report released last month studied the records of 9,691 male sex offenders from 15 states who were released from prison in 1994.

That study found that 5.3 percent of the released rapists were arrested for a new sex crime within three years of their release. Of those arrests, 40 percent allegedly committed the new offense within a year or less of their prison discharge.

The study also examined recidivism rates among 4,300 convicted child molesters who were released from prison in 1994. About 3.3 percent were arrested for another sex crime within three years of their release. Child molesters were, on average, five years older than predators who attacked adults; nearly 25 percent of child molesters were age 40 or older.

Although communities have tried to take stronger actions to tell residents a convicted sex offender is in the area, some groups say a few steps cross the line.

The American Civil Liberties Union (search) objected to a requirement in Corpus Christie, Texas — the state with the second-highest number of sex offender registrants — for these released criminals to place signs in their front yards that read "Danger! Registered Sex Offender Lives Here."

The ACLU won an injunction against the Sex Offender Alert Program in Albuquerque, N.M., which requires these ex-convicts to notify employers, landlords, home sellers and mortgagors of any convictions dating back to 1970. They also must register with the police and may be required to submit DNA samples, shoe size, and dental imprints.

But this type of punishment affects "the civil liberties of each of us individually," said George Bach, an attorney with the ACLU in New Mexico.

Keeping Offenders in Check

So what can society do to make sure sex offenders are kept in check?

For one, current laws for sex offenders need to be reformed, experts said.

"I know that's a surprise for everyone to hear, but I think you do need new laws," said former sex crimes prosecutor Pamela Hayes. "And you need laws that fit that type of behavior. And you need harsher laws that protect these people from society."

Former Polk County attorney Wayne Swanson, who put Rodriguez behind bars in 1980, suggested that more long-term treatment programs should be encouraged after prison sentences as a way of "keeping people that are still regarded as dangerous off the streets."

Of Rodriguez, he said: "He served 23 years. So, I don't know if increasing the length of the sentence by itself is going to solve our problems without creating huge prison overflows."

Jeff Goldenflame, who served five years in prison for molesting his 5-year-old daughter, was released from prison in 1991. He said Megan's Law (search), which requires sex offenders to register with local communities, works. If people know a sex offender is in their area, they should privately tell the felon his identification is known and he will be closely watched, Goldenflame said.

"Megan's law is not a panacea, all it does it let people know where the sex offenders are," Goldenflame said. "I think all of us have to be known to the public so that the community can keep its eye on us."