Concord — The New Hampshire House yesterday overwhelmingly approved legislation to toughen supervision and penalties for sexual predators while soundly defeating efforts to impose potential 25-year mandatory minimum sentences on first-time child rapists.

"I think what they are going by is the Constitution. … The punishment should fit the crime. If the crime is a particularly heinous crime — and I think all child offenses are heinous crimes, but some are worse than others — the punishment should not be the same for both," state Rep. David Welch, a Kingston Republican and chairman of the House Criminal Justice and Public Safety Committee, said after the 307-17 vote to approve the bill.

House lawmakers spent about an hour debating proposals to allow prosecutors to seek a 25-year mandatory minimum sentence for sexual assaults on children under 13.

"These are people who are predators. These are people who need to go away," said state Rep. Stanley Stevens, a Wolfeboro Republican and former police chief there who also serves on the Criminal Justice panel.

But other committee members said sexual offenders could not all be lumped together, and that many of them are related to their victims, making the need for some flexibility in punishment more important.

"I would say stick with the committee. We really studied this thoroughly, and we don't want mandatory sentences," said state Rep. William Knowles, a Dover Democrat who at one point cited statistics on the types of sex offenders from a series in the Valley News.

"We're after the pathological cases, and we're trying to keep them from hurting children in society, but, I say, let's be careful," added state Rep. Edward Moran, a Bedford Republican.

Two amendments to reinstate mandatory minimum sentences for first-time offenders into the bill failed, the first on a 264-76 vote, the other by 254-86. Among Upper Valley lawmakers, only state Reps. Christopher Irish, R-Claremont; Beverly Rodeschin, R-Newport; and Peter Franklin, D-Newport, supported one or both of the amendments.

Democratic Gov. John Lynch, who wants the 25-year mandatory minimum sentence, said he will push to reinstate the measure in the Senate bill.

"The mandatory minimum sentences we proposed would apply to the worst offenders who prey on the most vulnerable victims. The harm these predators do will stay with their young victims for the rest of their lives. The punishment should be commensurate with the crime," Lynch said in a written statement.

Still, the House bill does significantly advance a "Child Protection Act" sought by Lynch and Attorney General Kelly Ayotte.

The House bill allows court-approved civil commitments of a person deemed to be a "sexually violent predator" likely to strike again; strengthens registration requirements for sex offenders; establishes a study committee to look at classifying sex offenders so as to distinguish low-risk offenders from more violent predators; and also will employ global positioning satellite technology by July 2008 to track sex offenders who are back in the community.

It also increases the minimum sentences judges can, but are not required, to impose for sex crimes against young children from 10 years to up to 25 years. And state Rep. Lee Hammond, a Lebanon Democrat who serves on the Criminal Justice Committee, said the measure also allows prosecutors to seek a mandatory sentence of life in prison for some repeat offenders.

Hammond said such predators would have been through counseling and "will have been in the position of knowing better" than to repeat their crimes.

The House action in Concord yesterday mirrored, in some ways, a legislative vote in Montpelier last month where the Vermont House also rejected calls for mandatory minimum sentences for some sex offenders.

And, as in Montpelier, key members of the Senate Judiciary Committee want to incorporate mandatory minimums into their version of the bill.

"The Senate will look at the bill afresh and will put its own policy in place, and its own imprint on the legislation," said sate Sen. Joe Foster, a Nashua Democrat and chairman of the Senate Judiciary Committee.

Foster was an original sponsor of the bill with mandatory minimum sentences, and sounded undeterred despite the wide margin of defeat for such a proposal in the House.

"The Senate and the House often disagree on legislation, and they come together and work things out, and I expect that will happen in this piece of legislation as well," he said.