The drive to shield children from harm is one of the strongest instincts that we have as human beings. And setting limits on where convicted sex offenders can live is an idea that appeals to these protective instincts. But there’s no evidence that such restrictions keep children safe, and Yarmouth town councilors should reject a proposal that would make the community the latest in Maine to enact municipal sex offender residency restrictions.

Wednesday’s public hearing on the proposal — which would bar those convicted of child sexual crimes from living within a 750-foot radius of Yarmouth’s three schools — marks the second time in the past year that this issue has been debated by town councilors.

Backers of the ordinance pushed for residency restrictions last fall, after the school department told parents that a registered sex offender convicted of possessing child pornography had moved to a location near local schools. But the idea failed to attract enough support from the Town Council, prompting a successful signature-gathering drive to force the council to either take an up-or-down vote or send the proposal to voters. The council is expected to vote next week; to put the ordinance on the local referendum ballot in November.

Sending the issue to voters may be a good political move — 750 Yarmouth residents signed the petition, nearly double the number required to force a referendum — but it’s not an evidence-based one. The notion that strangers prey on children is belied by U.S. Justice Department research that has found that most sexually abused children are victimized by somebody they know well. Moreover, multiple studies show, residency restrictions not only keep sex offenders from finding work and re-entering the community but also make it harder for law enforcement officials to keep track of them.

The ineffectiveness of residency limits was cited by the Legislature’s Criminal Justice & Public Safety Committee in 2008, when it recommended in its “Study of Sex Offender Registration Laws” that legislators consider introducing a bill that would prohibit cities and towns from adopting their own restrictions on sex offenders. Such legislation was proposed in 2009 but was amended to allow Maine municipalities to impose the 750-foot barrier that’s now being sought in Yarmouth.

The state walked back its original proposal because it didn’t want to pre-empt local authority, Kate Dufour of the Maine Municipal Association told the Bangor Daily News in 2010, adding that “this was an important issue for municipalities.”

We agree that protecting children is important. One of the more heartening social developments of the past few decades is that we’ve learned more about the devastation suffered by children as a result of sexual crimes, as well as about the need to shield children from sexual predators. But the compromise allowed under state law has enabled Maine cities and towns to put in place regulations that don’t do what they’re intended to do — and Yarmouth shouldn’t be the next community to give in.