When sheriff's deputies alerted residents of family-friendly Highlands Ranch, Colo., that a registered violent sex offender (search) had chosen to begin a new life in their town, parents went into an uproar.
"We had the perception this was a safe place for children to be, and obviously fears have been raised," said one resident, John Whattam.
Along with some of his neighbors, Whattam is updating his security system and making sure his kids are never alone.
"Within walking distance, you have an elementary school, you have a middle school and a high school, you have parks," added Whattam.
Michael Carroll, 36, is a repeat sexual offender fresh out of prison. He's spent a total of 10 years in Florida jails for various sexual offenses with teenage boys. He's had no therapy, and he understands why neighbors don't want him next door.
"At this point right now, Mr. Carroll has no restrictions placed on him," said Lt. Alan Stanton of the Douglas County Sheriff's Dept. "He is not on probation, not on parole."
Carroll said he's looked as a "freak," and when asked if he thought he was still dangerous to neighborhood kids, he paused, then responded: "If I'm not supervised — yes."
Aside from a temporary sheriff's watch, Carroll is supervised by a former employer and his wife.
"Michael's a great guy, don't get me wrong, but that does not mean I will trust him as far as I can throw him," said Jerry Andrews, an ex-con himself who lives nearby.
Every state, and the federal government, has a Web site with a list of sex offenders. Private entities also run Web sites like www.mapsexoffenders.com, which provide lists of sex offenders in certain areas. According to the latest Bureau of Justice (search) statistics, Carroll is one of more than 386,000 registered sex offenders in the United States.
But those are just the ones who have been caught.
The issue of the sex offender next door has been spotlighted in recent headlines.
On Friday, police were questioning a convicted sex offender, 37-year-old Roger Bentley, who was suspected of abducting a 10-year-old girl from her home in Cedar Rapids, Iowa, setting off a statewide Amber Alert. Jetseta Marrie Gage was still missing as of 4 p.m. EST Friday, police said, although a body had been found.
Bentley is a registered sex offender. According to the state's Sex Offender Registry, he was convicted in 1994 in Benton County of lascivious acts with a child.
And in Florida, the man accused of kidnapping, sexually assaulting and killing 9-year-old Jessica Marie Lunsford is also a convicted sex offender. John Evander Couey (search), 46, was arrested in Georgia earlier this month, then brought back to Florida and booked on a probation violation and failure to register his change of address as required of a sex offender.
Jessica Lunsford was a third grader who was last seen the night of Feb. 23 when she went to bed after attending church.
Medical examiners said she was sexually assaulted and died of asphyxiation. Jessica's body was found early Saturday behind a house about 150 yards from her home, more than three weeks after she disappeared from her bedroom. Couey was staying with a relative in a house within eyeshot of the Lunsford home.
Eddie Freyer, a former FBI agent, told FOX News that sex offenders can't be concentrated in one place.
"You just can't put them in one or two locations, they have to go back out into communities," said Freyer, who worked on the case of Polly Klaas (search), a 12-year-old girl who was abducted from her home outside San Francisco and murdered.
He noted that some state laws require convicted offenders to actually return to the county where they committed their offenses once released from prison. "So that essentially puts them in just about every neighborhood in the country," he said.
U.S. Rep. Ted Poe, R-Texas, is trying to push a bill through Congress that would help keep better track of convicted sex offenders. The Child Predator Act (search) of 2005 would, among other things, require states to specify that a convicted predator must report a change of address within 10 days after the change of address takes effect. The law would also require that offenders notify schools, public housing and at least two media outlets of their whereabouts. Penalties for not complying with the law could mean up to two years in prison or hefty fines, according to the legislation.
The bill also calls on the FBI to set up an Internet site that includes a recent photograph and address of child predators.
"The real problem is, they want to remain anonymous so they can continue those ways" and abuse other children, Poe told FOX News on Friday, noting that recidivism rates for these offenders is high. "Hopefully we can do a better job keeping up with these people," he added.
Poe noted that the bill has 23 cosponsors and has been sent to the House Judiciary Committee. The next move is to get a sponsor for a sister measure in the Senate. Then, he said, lawmakers can "move it as fast as we can through the system."
He also noted that national figures such as John Walsh (search), host of "America's Most Wanted," also have thrown their support behind the measure in an effort "to plug up this loophole of predators moving throughout the system and us not knowing about them."
But Freyer said "there's only so much you can do" to keep offenders at bay. The best thing parents can do is to check their state sex offender registry to determine where convicted offenders are living so that they know if there is one in their neighborhood. Then, parents can take appropriate steps to protect their children.
"They're going to have opportunities and be exposed to children. They're going to be close to schools, they're going to have opportunities and unfortunately, they're going to seize the opportunities," Freyer said. "The key is to limit your child's exposure to these type of people — you find out where they are … and keep them away as best you can."
Click on the video box above for a complete report by FOX News' Carol McKinley.
FOX News' Liza Porteus contributed to this report.