NEW JERSEY A sex offender is suing over an ordinance restricting where he can live, mounting New Jersey’s first legal challenge to local laws that ban such convicts from taking up residence near schools, parks and playgrounds. More than a dozen New Jersey towns, including West Milford, have established so-called sex offender-free zones, but critics say the ordinances are ineffective in practice and unfair punishment for people who have already paid for their sins. In a civil suit filed last Monday, former teacher Steven Elwell, 34, said an ordinance passed in August by Lower Township in Cape May County effectively banishes him, his wife and their two young daughters from living there because its 2,500-foot buffer zone around schools, parks, day-care facilities and school bus stops encompasses almost the entire town. Elwell, a former wrestling coach at Lower Cape May Regional High School, spent a year in prison for having sex with a 16-year-old girl. He lives in Middle Township and wants to move to neighboring Lower Township, but he is hamstrung by the law, which bans him from living near or ``loitering’’ in or near the restricted areas, even if he is taking his own children to a park, according to the lawsuit. The ordinance violates the New Jersey Constitution by subjecting him to double jeopardy, depriving him of his right to live or move freely in Lower Township and injecting the town into the regulatory process New Jersey uses to deal with sex offenders, which has always been the province of the state, the suit claims. Supporters of the bans point to a ruling last April in which a circuit court upheld an Iowa statute giving municipalities the authority to pass such ordinances. Last week, the U.S. Supreme Court balked at hearing a challenge to the Iowa law. But John S. Furlong, a defense attorney active in sex offender litigation, predicted the Lower Township ordinance would be struck down. ``I don’t think these local ordinances are sustainable. They create a patchwork, they fail to conform with state constitutional principles and by the way, they’re just stupid. We have this bottomless well of municipal meddling in the private lives of people over whom they shouldn’t be allowed to exercise control,’’ he said.