And what about the children living at the park whose parents are not sex offenders and may not be aware that so many of their neighbors are?

“There is no way for me to know when someone who is not a sex offender comes and goes from there,” Bawden said. “There’s probably a waiting list for sex offenders out there.”

A female park tenant said she was made aware through word of mouth the number of sex offenders living there. A woman who lives in a nearby neighborhood said she learned of the makeup of the park by searching Iowa’s Sex Offender Registry.

Both women declined to be quoted by name, saying they are fearful of speaking critically of neighbors with a criminal history.

But the woman who lives on the outskirts of the park said her young daughter never is allowed outside the house alone because she and her husband are fearful of what could happen to her.

Experts who study public-safety measures geared toward sex offenders say residency restrictions like Iowa’s 2,000-foot rule are among the laws that don’t work. Critics do not quarrel with efforts to keep track of offenders but say zoning laws are not only ineffective but may actually increase public risk.