Megan Kanka, Polly Klaas, Jessica Lunsford -- the names break your heart at their very mention. All were victims of child sex predators.
But laws passed in their names may be making matters worse.
Across the nation, communities and legislators are enacting a wide variety of new laws to fight back against sex offenders. Some communities have set residency restrictions on sex offenders, others require GPS monitoring, and in Ohio there's a proposal that would require registered sex offenders to put bright green license plates on their vehicles.
But a growing chorus of experts said that many laws targeting sex offenders have backfired. And the consequences could be far-reaching.
"In 2005, we had a series of very high-profile, very violent brutal sex crimes against children,'' said Jill Levenson, a professor of human services at Lynn University in Florida. "And that really sparked a nationwide panic."
Residency restriction laws are among the most common new legislative efforts to address community concerns. Many states have enacted laws that bar offenders from living within 2,000 feet of a school or day care center. In California, the required distance is a quarter mile.
But the not-in-my-backyard mentality that has understandably prompted much of this legislation may be producing the opposite effect.
In Cedar Rapids, Iowa, Sheriff Don Zeller said new residency restrictions are forcing offenders into rural parts of the county where they are far harder to keep track of -- or worse, forcing them underground, where they can be lost track of completely.
"We're finding that it's almost impossible to keep track of individuals we have registered in the county,'' Zeller told ABC News' Law & Justice Unit. "Five years ago, we knew where about 95 percent of those individuals were. Now we're lucky if we know where 50, 55 percent of them are.''
And paradoxically, Zeller said, the new restrictions are also creating creepy sex offender "clusters'' -- like the Ced-Rel Motel in Lynn County, where more than two dozen sex offenders lived at one time.
"What if some individual comes in there with a family and decides that they're going to stay there overnight, not knowing that 26 sex offenders are living there? And what happens if then they expose their family because most families will send their kids down to get pop or ice and, unbeknown to them, there are 26 sex offenders living in that same complex?" Zeller said.
Polly Boland knows how that feels. Her family's farm sits beside a sex offender cluster.
"We told our kids that if anything peculiar is going on, to go back to the house,'' she said. "They're really aware of it. Our dog Henry is a good watchdog. … We don't feel unsafe, we wish they didn't live there," Boland said. "Other neighbors have thought about leaving, [but] we farm, and that's not something we can do."
Worse still for Zeller are offenders who are driven underground by the sometimes draconian residency restrictions in some cities. Overlapping exclusion zones keep sex offenders from finding residence in most of downtown Tulsa, Okla., and Atlanta.
ABC News found Mike Chalk, a 23-year-old registered sex offender, living in an EconoLodge hotel room in Iowa with three other offenders.